Most research has been in older adults with specific health conditions rather than healthy adults, and it's a prescription drug in some countries. Trials in healthy young adults are few, small and short: in a 7-day study of 48 college men, 250 or 500 mg a day made no difference in strength or reaction time, with mixed results on jumping.

Our amounts: Lock In Focus has 300 mg, within the 250–500 mg range used in short exercise studies. Sharp Mind's amount isn't listed separately, so it can't be compared.

Sources: Biggio & Mencacci 2025, review · Marcus et al. 2017, trial in healthy young men · Lee et al. 2021, JAMA Network Open cohort study

A 2015 systematic review of studies in healthy people found that high-quality trials on choline and thinking skills in adults are lacking. The NIH notes choline supplements haven't produced clear improvements in cognition in healthy adults. In 3 small experiments with young adults, a single 2.0–2.5 g dose of choline bitartrate didn't improve memory about an hour later.

Our amounts: In The Zone has 50 mg, well below the 550 mg Daily Value.

Sources: NIH Office of Dietary Supplements fact sheet · Leermakers et al. 2015, systematic review · Lippelt et al. 2016, memory experiments in young adults

Studied mostly in trials lasting about 12 weeks, using standardized extracts at 300–450 mg a day. A 2012 review of 6 trials in healthy adults found better scores on some memory recall tests but little change in other mental skills. A 2014 meta-analysis of 9 trials found small improvements in attention speed, and its authors called for larger, better-designed trials.

Our amounts: Amounts aren't listed separately in either product, so they can't be compared with the 300–450 mg of extract a day used in most studies.

Sources: Pase et al. 2012, systematic review · Kongkeaw et al. 2014, meta-analysis

Most research has been in older adults with memory complaints or specific health conditions rather than healthy adults. Some early studies used phosphatidylserine made from cow brain rather than soy. A 2006 review found only a handful of exercise studies, mostly using 750–800 mg a day, with mixed results on stress hormones and performance.

Our amounts: Amounts aren't listed separately in either product, so they can't be compared with studies, which used 100–800 mg a day.

Sources: Kingsley 2006, review of exercise studies · Kato-Kataoka et al. 2010, 6-month trial in older adults

Nearly all human research has been in older adults with specific health conditions rather than healthy adults, mostly in small trials that reviewers rated as low quality. It blocks an enzyme that breaks down acetylcholine, as some prescription drugs do, and it's sold as a prescription drug in China. There's very little research in healthy young adults.

Our amounts: Amounts aren't listed separately in either product. Studies used 300–500 mcg (micrograms) a day, which is less than 1 mg.

Sources: Yang et al. 2013, meta-analysis of 20 trials · Wang et al. 2009, meta-analysis · Ma et al. 2007, review

Most research has been in people with specific health conditions rather than healthy adults. Those studies have used amounts as high as 12 g a day. There's very little research on inositol for focus or sleep in healthy people.

Our amounts: Lock In Focus has 600 mg, while studies have used up to 12 g a day. The amounts in In The Zone and Deep Restore aren't listed separately.

Sources: Fitz et al. 2024, systematic review and meta-analysis · Mukai et al. 2014, meta-analysis · Carlomagno & Unfer 2011, safety review

There's very little modern human research on DMAE taken by mouth, and no systematic reviews of it in healthy adults. Older studies, many from the 1970s, were small trials in people with specific health conditions, and a 2018 Cochrane review rated that evidence as very low quality.

Our amounts: The amount isn't listed separately, and there's no well-studied amount to compare it with.

Sources: National Toxicology Program 2020, prenatal study in rats · Fisher et al. 2002, mouse embryo study · Cochrane review 2018, cholinergic medications

Research on glutamine supplements has mostly looked at exercise. A 2019 review of 47 studies in athletes found no effect on aerobic performance, body composition or immune measures, apart from a small drop in body weight. An earlier review noted that the usual reasons for taking it have little support from well-controlled studies in healthy, well-nourished people.

Our amounts: The amount isn't listed separately, so it can't be compared with exercise studies, which used grams rather than milligrams.

Sources: Ramezani Ahmadi et al. 2019, meta-analysis in athletes · Gleeson 2008, review of glutamine dosing

Most trials have been in older adults, usually giving DHA together with EPA. A 2020 review of 25 trials in older adults found no effect on overall thinking skills and a mild benefit for memory. The NIH concludes that omega-3 supplements don't appear to affect cognitive function in healthy older adults.

Our amounts: The amount isn't listed separately, so it can't be compared with studies, which used about 350–2,000 mg of DHA a day.

Sources: NIH Office of Dietary Supplements fact sheet · Alex et al. 2020, meta-analysis

Most trials have been small, with fewer than 200 people, and shorter than 3 months. A Cochrane review found no convincing evidence of better thinking skills in healthy people, and a 2024 meta-analysis of 15 trials found a small memory benefit but no change in attention or overall thinking. Most research shows no improvement in athletic performance.

Sources: NCCIH: Asian Ginseng · Cochrane review 2010, ginseng and cognition · Zeng et al. 2024, meta-analysis

Research on piperine has mostly looked at how it changes the way the body absorbs and breaks down other compounds, rather than at effects of its own. In short human studies, 15–20 mg a day raised blood levels of several prescription drugs. A 2021 safety review noted that few human studies looked closely at safety beyond these interactions.

Our amounts: Lock In Focus has 5 mg of extract and Grounded has 5 mg of black pepper. Supplements often provide 5–30 mg of piperine a day, and one estimate puts piperine from pepper in the average US diet at 14–54 mg a day.

Sources: Ziegenhagen et al. 2021, safety review · Lee et al. 2018, review of drug interactions

For most uses, NCCIH says research on green tea extract hasn't reached firm conclusions. A 2016 review of 34 controlled trials found liver-related side effects were rare and mostly mild liver-enzyme changes. Even so, NIH's LiverTox lists concentrated green tea extract as a well-established, though uncommon, cause of liver injury, usually within 1–6 months of starting.

Sources: NCCIH: Green Tea · NIH LiverTox: Green Tea · Isomura et al. 2016, liver safety review of 34 trials

A 2025 meta-analysis of 23 small trials (308 people) found a single 1–6 g dose was linked to small-to-moderate gains in exercise performance, but rated the evidence low to very low certainty. A 2025 review of 7 trials found no clear effect on cognitive scores. A 2025 review of 12 studies found caffeine plus taurine did better on reaction time than either alone, though results varied.

Our amounts: Amplify Energy's 1,000 mg is at the low end of the 1–6 g range used in performance studies. Amounts in Stage Rush and Deep Restore aren't listed separately, so they can't be compared.

Sources: Deng et al. 2025, single-dose meta-analysis · Cao et al. 2025, cognition meta-analysis · Deng et al. 2025, caffeine and taurine review

Results are mixed. A 2015 review found the most consistent results for short-term mental performance in stressful or mentally demanding situations, with little sign of benefit outside those conditions. For exercise, a 2023 meta-analysis of 8 studies found no effect on endurance performance, rating the evidence moderate quality.

Sources: Jongkees et al. 2015, review of stress and cognition studies · Solon-Júnior et al. 2023, endurance meta-analysis

NIH notes that B12 is often promoted for energy and athletic performance, but supplements appear to have no benefit for performance in people who aren't low in B12. Low B12 is more common in people who eat few animal foods and in older adults.

Our amounts: The Daily Value is 2.4 mcg; most of our products meet or exceed it, while Lock In Focus, Amplify Energy and Flow State Hydration have 0.8 mcg (33% DV). At 1,000 mcg the body absorbs only about 1.3%.

Sources: NIH Office of Dietary Supplements fact sheet · NIH Office of Dietary Supplements: Vitamin B12 for consumers

More than 1,000 studies have been done since the early 1990s. Short-term use often increases strength and performance in brief, high-intensity efforts, but it seems to be of little value for endurance sports, and responses vary between people. Studies typically used 20 g a day for 5–7 days, then 3–5 g a day. Most research used creatine monohydrate, the most studied form.

Our amounts: Stage Rush has 1,500 mg of dicreatine malate, which supplies less creatine than the 3–5 g a day maintenance amount used in studies, and in a less-studied form.

Sources: NIH Office of Dietary Supplements: Exercise and Athletic Performance · ISSN position stand 2017, creatine safety and efficacy

A 2017 meta-analysis of 40 placebo-controlled studies (1,461 people) found a small overall benefit, with exercise duration affecting results and the clearest effects in capacity tests lasting 30 seconds to 10 minutes. NIH notes this research is dominated by small, short studies with varied protocols, and results for endurance activities like cycling conflict. Studies showing benefits typically used 4–6 g a day for at least 2–4 weeks.

Our amounts: Stage Rush has 750 mg per serving, well below the 4–6 g a day used in most studies.

Sources: Saunders et al. 2017, meta-analysis of 40 studies · NIH Office of Dietary Supplements: Exercise and Athletic Performance · ISSN position stand 2015, beta-alanine

NIH's review found that 2–20 g a day had little to no effect on aerobic or anaerobic exercise performance. A 2020 meta-analysis of 15 studies reported improvements, but a 2025 published critique found errors in how it pooled results. Overall, the evidence is limited and conflicting.

Our amounts: Our 300–1,500 mg per serving is below the 2–20 g a day used in the performance studies NIH reviewed.

Sources: NIH Office of Dietary Supplements: Exercise and Athletic Performance · Viribay et al. 2020, meta-analysis · Trexler 2025, critique of the 2020 meta-analysis

A 2026 review of 30 small trials (644 people) found a small overall improvement in exercise performance and no clear effect on perceived effort, rating the certainty of evidence low to very low. NIH says the research doesn't strongly support a performance benefit, and one study found citrulline alone led to poorer treadmill performance than placebo. Reliable doses haven't been established.

Our amounts: The amount isn't listed separately, so it can't be compared with the 8 g used in the best-known weightlifting study.

Sources: Wang et al. 2026, meta-analysis of 30 trials · NIH Office of Dietary Supplements: Exercise and Athletic Performance

A 2024 meta-analysis of 17 small trials (317 people, 21% women) found that taking betaine for at least 7 days improved maximal strength, mainly in the lower body, with no clear effect on upper-body strength, sprint power or muscular endurance. NIH notes earlier studies were small, mostly in men, and gave modest, conflicting results at 2–5 g a day for up to 15 days.

Our amounts: The amount isn't listed separately, so it can't be compared with the 2–5 g a day used in studies.

Sources: Zawieja et al. 2024, meta-analysis of 17 trials · NIH Office of Dietary Supplements: Exercise and Athletic Performance

There's very little human research on glycocyamine (also called guanidinoacetic acid) on its own. A 2016 review found only a few studies in physically active adults suggesting possible performance benefits, along with older research from the 1950s. A 2021 safety review noted that animal studies reported toxic effects when it builds up, and that it may raise blood homocysteine.

Sources: Ostojic 2016, review of performance research · Ostojic 2021, safety review

There's very little human research on glucuronolactone on its own. Energy drink studies test it mixed with caffeine, taurine and sugar, and reviews conclude that caffeine and carbohydrate appear to be the main active ingredients in these drinks. A 2022 risk assessment estimated that typical energy drink intakes supply about 600–1,200 mg.

Sources: ISSN position stand 2023, energy drinks and shots · Antonio et al. 2024, energy drink evidence review · Rubio et al. 2022, energy drink risk assessment

Very little research has looked at waxy maize starch specifically. In two small 1996 studies of 8 and 10 male cyclists, waxy starch refilled muscle glycogen about as well as glucose, and taken before a ride it increased work output about as much as glucose did compared with a placebo. These studies used large amounts, about 1 g per kg of body weight or more, and didn't show an advantage over other carbs.

Sources: Jozsi et al. 1996, glycogen and cycling study · Goodpaster et al. 1996, pre-exercise starch study

A 2020 systematic review of 14 placebo-controlled trials found limited evidence for lower stress and very limited evidence for better sleep. It's still unclear how much GABA taken by mouth reaches the brain, and an earlier review noted that much of the supportive research came from researchers with possible conflicts of interest.

Our amounts: Unwind Strips has 25 mg, within the 20–100 mg range used in the stress studies but below the 100–300 mg used in the sleep studies. The amount in our other products isn't listed separately.

Sources: Hepsomali et al. 2020, stress and sleep systematic review · Boonstra et al. 2015, GABA as a food supplement review · USP safety review of GABA, 2021

Most people get magnesium from food such as nuts, seeds, leafy greens and whole grains. Sleep research is limited: a 2021 review of 3 small trials in older adults found people fell asleep about 17 minutes sooner, but rated the evidence low to very low quality. A 2020 Cochrane review found magnesium unlikely to prevent muscle cramps in older adults, and found no trials on exercise-related cramps.

Sources: NIH Office of Dietary Supplements fact sheet · Mah & Pitre 2021, sleep review · Cochrane review 2020, muscle cramps

Human research is limited and mostly small trials on sexual desire. A 2010 review found only 4 trials, too few and too low in quality for firm conclusions, and a 2026 review reported more consistent results in men than in women. A 2024 review of exercise performance found 21 studies, but only 4 were in people, too few to combine.

Our amounts: Grounded Plus has 150 mg, far less than the roughly 3 g a day of maca powder used in most human trials.

Sources: Shin et al. 2010, sexual function systematic review · Bloomer 2026, maca and libido review · Huerta Ojeda et al. 2024, physical performance meta-analysis

There's very little human research on shatavari as a supplement for stress or energy, and the few human trials on other uses have been small and poorly designed. A 2021 review noted that a lack of standardized extracts has held research back.

Sources: Mortel & Mehta 2013, systematic review of herbal trials · Majumdar et al. 2021, Asparagus racemosus review

The best evidence is for jet lag, especially after flying east. In people whose sleep schedule naturally runs late, trials found they fell asleep about 20–35 minutes sooner. For long-term trouble sleeping, the evidence isn't strong enough for experts to recommend it, and studies in shift workers are small and inconclusive. Long-term safety hasn't been well studied, especially at amounts higher than the body makes on its own.

Sources: NCCIH: Melatonin, what you need to know

Most research has been in people with specific health conditions rather than healthy adults, and a 2020 review judged those studies relatively weak, since few compared 5-HTP with a placebo. There's very little research on everyday use for sleep or mood in healthy adults. The most common side effects are nausea and other stomach upset, which become more likely at higher doses.

Sources: Javelle et al. 2020, systematic review and meta-analysis · Maffei 2020, 5-HTP physiology and toxicology review

A 2022 meta-analysis pooled 4 trials and found less time awake during the night, especially at 1 g a day or more, but no change in other sleep measures. A 2021 review of 11 trials in healthy adults found 4 that reported better mood than placebo, using 0.14–3 g a day, and the authors said better-designed studies are needed.

Our amounts: The amount in Deep Restore isn't listed separately, so it can't be compared with the 1 g or more a day linked to the clearest sleep results.

Sources: Sutanto et al. 2022, sleep meta-analysis · Kikuchi et al. 2021, mood systematic review · Das et al. 2004, 5-HTP and tryptophan safety review

Most research has been in people with specific health conditions rather than healthy adults. For other uses, NCCIH says the evidence is too limited to draw conclusions. It appears safe for up to 12 weeks for most adults who aren't taking any medicine, but it can interact with many medicines in dangerous ways.

Sources: NCCIH: St. John's Wort

A 2024 review of 10 trials (772 people) found better sleep-quality scores when 5 trials were pooled, though results varied widely, and no change in sleep length, sleep efficiency or daytime tiredness. Only one study checked product purity. NCCIH says research overall hasn't produced enough reliable evidence to rate how useful chamomile is.

Sources: Kazemi et al. 2024, sleep meta-analysis · NCCIH: Chamomile

Results for sleep have been inconsistent. A systematic review of 9 placebo-controlled trials judged them insufficient to show whether valerian works, and in one small trial 450 mg shortened the time to fall asleep by about 7 minutes, which the authors said probably wasn't meaningful. NCCIH says there isn't enough evidence on stress either.

Our amounts: Drift Sleep Strips has 50 mg of extract, much less than the 400–900 mg used in the sleep trials.

Sources: NCCIH: Valerian · NIH Office of Dietary Supplements fact sheet

A 2026 review of 11 trials (628 adults) found lavender essential oil improved sleep quality, but the authors said the small number and quality of studies means this needs confirming. Studies of lavender taken by mouth have mostly been in people with specific health conditions, and NCCIH notes they were small with little independent funding. It says more high-quality research is needed.

Sources: Shen et al. 2026, sleep meta-analysis · NCCIH: Lavender

Human research is limited to a small number of trials, mostly in people with specific health conditions rather than healthy adults. A 2021 review warned that results varied widely between studies, and a 2025 review of sleep and memory studies said stronger evidence from more rigorous trials is needed.

Sources: Ghazizadeh et al. 2021, systematic review and meta-analysis · Oliveira et al. 2025, cognition and sleep review · NIH LiverTox: Lemon Balm

It hasn't been studied much. A 2020 review found just 9 trials, lasting 1 to 30 days, mostly in people with specific health conditions rather than healthy adults. NCCIH says a small amount of research has looked at sleep, with mixed results for falling and staying asleep, and that there isn't enough evidence for other uses.

Sources: NCCIH: Passionflower · Janda et al. 2020, systematic review

Most human studies tested hops combined with valerian, not hops on their own. A 2010 review of 16 studies in adults with ongoing sleep problems found 12 linked valerian, alone or with hops, to improvements in some sleep measures, like time to fall asleep, but the studies were designed very differently. A 2015 review of placebo-controlled trials concluded that valerian, alone or with hops, showed limited benefit for sleep.

Our amounts: The amount in Deep Restore isn't listed separately, and studies mostly used hops in fixed combinations with valerian, so it can't be compared.

Sources: Salter & Brownie 2010, valerian and hops review · Culpepper & Wingertzahn 2015, sleep aids systematic review

Most research on this root has been done in the lab and in animals, and we found no well-designed trials of it as a supplement in healthy adults. A 2019 review of its pharmacology called for more research on how its compounds are absorbed and used by the body before conclusions can be drawn.

Sources: NIH LiverTox: Skullcap · Zhao et al. 2019, pharmacology and toxicology review

Human trials have mostly measured heart and metabolic markers in small groups, with small effects seen mainly with whole berries rather than extracts, and no change in blood pressure. Reviewers of 10 and 5 trials called for larger studies.

Our amounts: The amount in Deep Restore isn't listed separately. In the 2022 review, effects were clearer with whole berries than with extracts.

Sources: Toh et al. 2022, wolfberry meta-analysis · Zeng et al. 2023, blood lipids meta-analysis · Rivera et al. 2012, goji and warfarin case report

Studied mainly as a tea or capsule for heart and metabolic markers, not sleep. Reviews of 17 and 26 trials found small changes, mostly in people with specific health conditions, and said there were too few studies to set a dose.

Our amounts: Drift has 10 mg of extract, below the 15 mg to 9 g a day used in trials.

Sources: Ellis et al. 2022, blood pressure meta-analysis · Norouzzadeh et al. 2025, umbrella review

In a 2025 summary, NIH concluded there isn't enough evidence to say whether turmeric or curcumin, its main compound, benefits any health purpose. Most research has been in people with specific health conditions rather than healthy adults. Products in studies varied a lot in how much curcumin they contained, which makes results hard to compare.

Our amounts: Encore has 20 mg of extract. Studies cited by NIH's LiverTox used about 500–1,500 mg of curcumin a day.

Sources: NCCIH: Turmeric · NIH LiverTox: Turmeric

Human research is limited. A 2020 review found 26 clinical studies using different parts of the plant, mostly in people with specific health conditions, and many had a high risk of bias. It concluded there isn't enough clinical evidence to support most traditional uses. A 2024 review of 215 studies found only 16 were done in people.

Sources: Bagherzadeh Karimi et al. 2020, clinical trials review · Mahomoodally et al. 2024, systematic review

Most research has been in people with specific health conditions rather than healthy adults, and a 2017 review of 33 trials rated their overall quality as poor. Side effects reported in trials were mostly mild stomach upset. A 2025 review of 6 trials found raised liver enzymes were the most common side effect, though they went away without serious problems.

Our amounts: Encore has 15 mg of extract. Most trials in the 2025 review used extracts giving 180 mg a day of andrographolide, one of the herb's main compounds.

Sources: Hu et al. 2017, clinical trials meta-analysis · Prabhakornritta et al. 2025, clinical trials meta-analysis · Kaewdech et al. 2022, liver enzyme study

Most human research has looked at inulin, a fiber from chicory root, rather than chicory extracts. A 2023 review of 50 trials (2,525 people) found 3–20 g a day of chicory inulin raised levels of Bifidobacterium, a common gut bacterium, and improved bowel function measures in healthy people. We found little human research on chicory extracts themselves.

Our amounts: Encore has 15 mg of extract, far below the 3–20 g a day of inulin used in those studies.

Sources: Nagy et al. 2023, chicory inulin meta-analysis

Most human research has used grape seed extract and measured heart and metabolic markers, with small or mixed results across reviews of 11 and 19 small studies. NIH says there isn't enough research to judge other uses.

Sources: NCCIH: Grape Seed Extract

Most research has been in people with specific health conditions rather than healthy adults. A 2020 review found only 2 controlled human studies that met its standards and called the clinical evidence limited. A 2025 review of 16 human and animal studies reported no significant side effects.

Sources: Dhawan & Olweny 2020, clinical meta-analysis · Iregui-Parra et al. 2025, systematic review

Two 2023 reviews of 9 and 5 small randomized trials measured heart and metabolic markers in adults taking 500–1,500 mg a day for 2–12 weeks and found some changes. The reviewers said results varied a lot across the small number of trials and should be read with caution.

Our amounts: Encore has 15 mg of extract, far less than the 500–1,500 mg a day used in these trials.

Sources: Brown et al. 2023, meta-analysis of 9 trials · Setayesh et al. 2023, meta-analysis of 5 trials

Most Americans get less than recommended from food; potatoes, beans, dried fruit, milk and orange juice are good sources. Only a very small amount is lost in sweat. Most supplement research has been in people with specific health conditions rather than healthy adults, and the few trials in healthy older adults had mixed results for bone health.

Our amounts: Each product has 200 mg or less (4% DV or less of the 4,700 mg Daily Value); there's no Upper Limit for potassium.

Sources: NIH Office of Dietary Supplements fact sheet

Dairy supplies most of the calcium in US diets, and many Americans get less than recommended. Supplement results in healthy older adults are mixed: a review of 14 trials found calcium alone didn't lower hip fracture risk, and a review of 41 trials found no effect on body weight or body fat. Studies on calcium supplements and heart health disagree.

Our amounts: Stage Rush has the most at 170 mg (13% DV of 1,300 mg); the other products have 50 mg or less. The Upper Limit is 2,500 mg a day for adults 19–50 and 2,000 mg for those 51 and older.

Sources: NIH Office of Dietary Supplements fact sheet

Most people in the US get enough niacin and B6 from food, especially fortified cereals, meat, fish and starchy vegetables. A 2019 review of 16 trials with about 2,000 people found that taking several B vitamins for at least 4 weeks led to a small improvement in self-reported stress, but not in other mood measures. A review of 14 trials found B6 didn't improve memory or thinking.

Our amounts: The Multivitamin has thiamin 7 mg (583% DV, as thiamine mononitrate), riboflavin 7.5 mg (577% DV), niacin 30 mg NE (188% DV), pantothenic acid 10 mg (200% DV, as D-calcium pantothenate) and vitamin B6 7.5 mg (441% DV, as pyridoxine HCl). B6 ranges from 1.8 mg (106% DV) in Deep Restore to 12 mg (706% DV) in In The Zone, and Sharp Mind has 8 mg of niacin (50% DV). The US Upper Limits are 100 mg a day for B6 and 35 mg a day for niacin from supplements.

Sources: NIH ODS fact sheet: Vitamin B6 · NIH ODS fact sheet: Niacin · Young et al. 2019, B vitamins and mood meta-analysis

Most people in the US get enough from leafy greens, beans, fruit and fortified grains like bread and cereal. Anyone who could become pregnant is advised to get 400 mcg of folic acid a day from supplements, fortified foods or both. In older adults, a review of 11 trials with over 20,000 people found folic acid didn't improve memory or thinking.

Our amounts: 680 mcg DFE (170% DV) equals about 400 mcg of folic acid; the Upper Limit is 1,000 mcg of folic acid a day from supplements and fortified foods (folate from food doesn't count).

Sources: NIH Office of Dietary Supplements fact sheet

Deficiency is rare in people who eat a normal mixed diet; eggs, fish, meat, seeds and nuts are good sources. Popular claims for hair, skin and nails rest on a few case reports and small studies without placebo groups, and the NIH says it's still unknown whether biotin improves them in healthy people.

Our amounts: The Multivitamin has 300 mcg (1,000% DV of 30 mcg) and In The Zone has 3 mcg (10% DV); no Upper Limit has been set because no toxicity has been seen.

Sources: NIH Office of Dietary Supplements fact sheet

Deficiency is uncommon in the US, where fewer than 1% of people have low blood levels. Large long-term trials in generally healthy adults found beta-carotene supplements had no effect on the main health outcomes studied, including one in 22,071 male doctors who took 50 mg every other day for 12 years.

Our amounts: The Multivitamin has 600 mcg RAE (67% DV of 900 mcg) and In The Zone has 122 mcg RAE (14% DV). The 3,000 mcg Upper Limit applies only to preformed vitamin A, not beta-carotene.

Sources: NIH Office of Dietary Supplements fact sheet

Most people in the US get enough from fruits and vegetables such as citrus, peppers, tomatoes and potatoes. Large trials that gave adults 120–500 mg a day for 5–10 years mostly found no effect on the major long-term health outcomes they studied.

Our amounts: The Multivitamin has 150 mg (167% DV of 90 mg) and In The Zone has 125 mg (139% DV); the adult Upper Limit is 2,000 mg a day.

Sources: NIH Office of Dietary Supplements fact sheet

Sunlight and fortified foods like milk and cereal supply most people's vitamin D, but over 90% of Americans get less than recommended from food alone. In the VITAL trial of about 26,000 generally healthy adults 50 and older, 50 mcg a day for about 5 years didn't lower fracture risk. Outside bone health, the NIH calls the evidence inadequate or inconsistent.

Our amounts: Grounded Plus has 20 mcg (100% DV), the Multivitamin 10 mcg (50% DV) and In The Zone 3 mcg (15% DV); the adult Upper Limit is 100 mcg (4,000 IU) a day.

Sources: NIH Office of Dietary Supplements fact sheet

Many Americans get less than recommended from food, though surveys may miss cooking oils. Large trials in tens of thousands of healthy middle-aged and older adults, using 180–400 mg doses for 5–10 years, found little or no benefit for the major long-term outcomes studied, and some found small increases in certain risks.

Our amounts: In The Zone has 40 mg (266% DV; the Daily Value is 15 mg) and the Multivitamin has 13.5 mg (90% DV), both as DL-alpha tocopheryl acetate; the adult Upper Limit for supplements is 1,000 mg a day.

Sources: NIH Office of Dietary Supplements fact sheet

Most people in the US get enough from meat, seafood, dairy, eggs and fortified cereals, though about 15% of adults fall short. Most supplement research has been in people with specific health conditions rather than healthy adults.

Our amounts: The Multivitamin has 15 mg (136% DV of 11 mg) and In The Zone has 10 mg (91% DV); the adult Upper Limit is 40 mg a day from all sources.

Sources: NIH Office of Dietary Supplements fact sheet

Most people in the US get enough from bread, grains, meat, seafood and eggs. Large trials in tens of thousands of adults, mostly men, found that 200 mcg a day for about 5 years didn't change the major long-term health outcomes they studied. Trials in older adults who already got enough also found no effect on memory or thinking.

Our amounts: In The Zone has 50 mcg (91% DV of 55 mcg) and the Multivitamin has 30 mcg (55% DV); the adult Upper Limit is 400 mcg a day from all sources.

Sources: NIH Office of Dietary Supplements fact sheet

Typical US diets meet or exceed the recommended amount, with shellfish, nuts, seeds and organ meats as top sources. Research on copper supplements in healthy people is limited to a few small trials, such as one in 70 adults where 2 mg a day for 8 weeks raised copper enzyme activity but didn't change heart health markers.

Our amounts: The Multivitamin has 2 mg (222% DV of 0.9 mg) and In The Zone has 0.052 mg (6% DV); the adult Upper Limit is 10 mg a day.

Sources: NIH Office of Dietary Supplements fact sheet

Grains, tea, vegetables, nuts and legumes are the main sources, and the limited data suggest most people get enough. No clinical trials have tested manganese supplements alone for bone health, human trials in other areas are lacking, and the NIH says more research is needed.

Our amounts: The Multivitamin has 2 mg (87% DV of 2.3 mg) and In The Zone has 0.4 mg (17% DV); the adult Upper Limit is 11 mg a day.

Sources: NIH Office of Dietary Supplements fact sheet

Most research has been in people with specific health conditions rather than healthy adults. A 2016 review found chromium didn't change blood sugar levels in healthy people.

Our amounts: The Multivitamin has 120 mcg (343% DV of 35 mcg), Stage Rush 30 mcg (86% DV) and In The Zone 12 mcg (34% DV); no Upper Limit has been set.

Sources: NIH Office of Dietary Supplements fact sheet

Legumes, grains, leafy vegetables and milk provide plenty, and deficiency has only been seen in people with a rare genetic condition. There's very little human research on molybdenum supplements.

Our amounts: The Multivitamin has 75 mcg (167% DV of 45 mcg) and In The Zone has 10 mcg (22% DV); the adult Upper Limit is 2,000 mcg a day.

Sources: NIH Office of Dietary Supplements fact sheet

Meat and seafood are the richest sources, along with beans, nuts, vegetables and fortified grains. Groups more likely to need extra include pregnant women, women with heavy periods and frequent blood donors. Most supplement research has been in people with low iron or specific health conditions rather than healthy adults.

Our amounts: In The Zone has 2.6 mg (14% DV of 18 mg); the adult Upper Limit is 45 mg a day.

Sources: NIH Office of Dietary Supplements fact sheet

Boron isn't considered essential, and most adults get about 1–1.5 mg a day from foods like coffee, milk, apples and beans. Human research on boron supplements is limited to a few small, short trials. Vanadium research has mostly been in animals or people with specific health conditions, and a 2016 review noted the few human studies were very short and raised concerns about buildup with long-term use.

Our amounts: The amounts aren't listed separately, so they can't be compared with the 20 mg a day Upper Limit for boron.

Sources: NIH ODS fact sheet: Boron · Domingo & Gómez 2016, vanadium review

Most research has been in men with specific health conditions rather than healthy adults. In that research, a 2023 Cochrane review of 27 trials (4,656 men) found saw palmetto alone made little or no difference to symptoms or quality of life, based on high-certainty evidence, and NIH-funded trials at up to 3 times the usual dose also found no benefit. Evidence for other uses, such as hair loss, is too limited to draw conclusions.

Sources: NCCIH: Saw Palmetto · Cochrane review 2023, saw palmetto

Most research has been in men with specific health conditions rather than healthy adults. A 2007 review found the evidence came mostly from open studies without a placebo group, plus a few randomized trials of one specific extract, and said the size of any effect still needed confirming. Lab and animal findings may not carry over to people.

Sources: Chrubasik et al. 2007, nettle root review

A 2021 review of 46 studies in adults with healthy eyes found lutein raised macular pigment, a measure of these pigments in the eye, at 5 mg a day or more for 3–12 months, but not below 5 mg. A 2021 meta-analysis found no significant effect of lutein on attention, memory or planning skills. For lycopene, a 2020 review of 43 trials found no significant effect on blood pressure or cholesterol.

Our amounts: The amounts aren't listed separately, so they can't be compared with the 5 mg or more of lutein a day used in the eye studies.

Sources: Wilson et al. 2021, lutein and macular pigment meta-analysis · Li & Abdel-Aal 2021, lutein and thinking skills meta-analysis · Tierney et al. 2020, lycopene meta-analysis

Most research has looked at specific illnesses rather than everyday wellness, and a 2014 Cochrane review of 24 trials found no clear benefit, at most a weak effect from some products. Products differ widely in species, plant part and extraction, which makes studies hard to compare. In athletes, a 2024 review of 6 small studies found no effect on aerobic capacity or red blood cell measures.

Sources: NCCIH: Echinacea · Cochrane review 2014, echinacea · Deccy et al. 2024, echinacea in athletes meta-analysis

There's no systematic review of human trials of yeast beta glucan, and most studies have looked at specific illnesses rather than everyday wellness. In the largest, 299 healthy adults took 900 mg a day for 16 weeks; how often they got sick didn't change, though early symptoms were milder. A 100-person trial at 250 mg a day found no significant differences.

Our amounts: The amount isn't listed separately, so it can't be compared with the 250–900 mg a day used in trials.

Sources: Dharsono et al. 2019, randomized trial · Fuller et al. 2017, randomized trial

Most research has been in people with specific health conditions rather than healthy adults. In people who exercise, a 2022 review of 13 studies found the evidence scarce and inconsistent: some signs of better oxygen use during moderate exercise, no clear effect in power athletes, and no solid data on immune function. A 2011 US Pharmacopeia review gave spirulina its top safety rating.

Sources: NIH LiverTox: Spirulina · Calella et al. 2022, spirulina and exercise review · USP safety review 2011, spirulina

Most research has been in people with specific health conditions rather than healthy adults. On immune function in healthy people, a 2022 systematic review found only two studies suggesting a possible benefit, and both were small with research weaknesses. Oral garlic has been used safely in studies lasting up to 7 years.

Sources: NCCIH: Garlic · Crawford et al. 2022, immune supplements review

Most research has been in people with specific health conditions rather than healthy adults, and results have conflicted. NCCIH says there's little or no quality evidence on hawthorn for most uses, and no studies have tested use beyond 16 weeks.

Sources: NCCIH: Hawthorn

Most research has been in people with specific health conditions rather than healthy adults, and NCCIH says research doesn't clearly support cinnamon for any health use. Studies often don't say which species or plant part was tested, and controlled trials have given conflicting results.

Our amounts: The amount isn't listed separately in either product, so it can't be compared with the 1–2 g a day typically used in supplements.

Sources: NCCIH: Cinnamon · NIH LiverTox: Cinnamon

NCCIH says many bilberry studies were small or not rigorous, and bilberry hasn't been clearly shown to help any health condition. A 2004 review of 12 placebo-controlled night vision trials, nearly all in healthy people, found the 4 most recent randomized trials were all negative; positive results came from weaker studies.

Our amounts: The amount isn't listed separately in either product, so it can't be compared with the up to 160 mg a day of extract used in research, which appeared well tolerated for up to 6 months.

Sources: NCCIH: Bilberry · Canter & Ernst 2004, night vision review

A 2020 meta-analysis of 9 trials found a small improvement in sport performance with New Zealand blackcurrant, at 105–210 mg of anthocyanins before exercise, and a 2026 review of 21 small crossover trials rated that evidence low certainty. For pomegranate, a 2025 meta-analysis of 10 studies found no significant effect on muscle soreness or most recovery markers after exercise.

Our amounts: The amounts aren't listed separately, so they can't be compared with the 105–210 mg of blackcurrant anthocyanins used in the exercise studies.

Sources: Braakhuis et al. 2020, blackcurrant meta-analysis · Gholamian et al. 2026, blackcurrant review · Belyani et al. 2025, pomegranate meta-analysis

There's very little human research on grapefruit seed extract. Lab tests of commercial extracts found synthetic preservatives, mainly benzethonium chloride, in 5 of 6 products in one study and 7 of 9 in another, and extracts without them showed no antimicrobial activity. Olive leaf extract research has mostly measured heart-health markers; a 2022 review of 12 trials (819 adults) found small changes, largest in people with specific health conditions.

Sources: von Woedtke et al. 1999, grapefruit seed extract testing · Ganzera et al. 2006, grapefruit seed extract testing · Razmpoosh et al. 2022, olive leaf meta-analysis