Over-the-counter supplements

Small trials in young men: a better score on one attention test an hour after a dose, and more jump power or leg strength after about a week. Other measures did not move. In South Korea it is a prescription drug widely used for dementia symptoms.

Trade-off: A Korean records study of about 12 million people linked use to a higher 10-year stroke risk. That kind of study cannot prove cause.

When: Usually taken earlier in the day. No study compares timing.

Example: Sports Research Alpha GPC. brand site. Link checked, not paid.

Most people in the US get less than the recommended amount. A 2015 review of 13 studies found no clear thinking boost in healthy adults.

Trade-off: Very high intake can cause fishy body odor, sweating and low blood pressure. The NIH fact sheet gives the adult upper limit.

When: Usually taken earlier in the day. No study compares timing.

Example: Sports Research Choline. brand site. Link checked, not paid.

A review of nine Bacopa trials found quicker attention and reaction time in trials lasting 12 weeks or more. Phosphatidylserine trials disagree: a large cow-brain trial run by its maker found memory gains in older patients who already had serious thinking problems, and a soy trial in older adults with memory complaints found none. We found no placebo-controlled trial of the two together.

Trade-off: Bacopa often upsets the stomach. Effects take weeks, not hours.

When: Bacopa is easier on the stomach with food.

Example: X Gold Health Phosphatidylserine + Bacopa. No link. We could not verify one.

In a Japanese trial of 30 older adults with mild memory loss, scores improved over 16 weeks. They dropped again four weeks after stopping.

Trade-off: Few human trials, all small. Products vary a lot.

When: No timing data.

Example: Sports Research Organic Lion's Mane. product page. Link checked, not paid.

In a small trial, theanine with a little caffeine sharpened focus and accuracy 60 to 90 minutes after a dose.

Trade-off: Effects are mild. Few long-term studies.

When: Trials tested it in the morning with caffeine, and in the evening.

Example: Sports Research L-Theanine. brand site. Link checked, not paid.

A 2026 review of 34 trials in 1,769 people found people rated their own low mood and anxiety as better on saffron than on placebo. Ratings by clinicians did not improve.

Trade-off: The two kinds of rating disagree, so the real effect is unclear. The reviewers asked for better trials. High doses are not safe in pregnancy.

When: Timing varied across trials.

Example: Sports Research Saffron. brand site. Link checked, not paid.

A 12-week trial of 44 older adults with thinking problems, run by the maker, reported better thinking scores. A 2026 trial in 100 adults with poor sleep found a better overall thinking score. People rated some sleep problems as better, but a sleep tracker showed no change.

Trade-off: The first trial was run by the maker. Costs more than other forms of magnesium.

When: Often taken in the evening. No study compares timing.

Example: Sports Research Magtein. brand site. Link checked, not paid.

Most human trials used the precursors NR or NMN. A 2025 review of those trials found no gain in muscle or strength in older adults.

Trade-off: Swallowed NAD+ itself has little human data. Long-term effects are unknown.

When: Usually taken in the morning. No study compares timing.

Example: Vinatura NAD+. rating page. Link checked, not paid.

An FDA-approved hospital antidote for acetaminophen overdose. In chronic bronchitis trials it cut flare-ups. A review of seven studies found no real gain in exercise performance.

Trade-off: The drug label lists nausea and vomiting. In the bronchitis trials, stomach complaints were about as common on placebo. The FDA says it does not count as a supplement, but allows it to be sold as one for now.

When: Often taken with food. No study compares timing.

Example: Sports Research NAC. brand site. Link checked, not paid.

In a 4-week trial of 20 obese adults, insulin sensitivity in liver and muscle rose about 30%. A large ALS trial of a TUDCA combination drug found no benefit.

Trade-off: Long-term data in healthy people is thin. A label that says proprietary blend does not tell you how much TUDCA is inside.

When: Usually taken with meals. No study compares timing.

Example: HumanX Tudca+. retailer page. Link checked, not paid.

The label lists milk thistle first in its blend, so milk thistle is the largest share. The amount of TUDCA is not stated.

In a two-year trial of 420 heart failure patients, major heart events hit 15% on CoQ10, against 26% on placebo. A review of 12 small trials found it eased statin muscle aches.

Trade-off: Absorbs poorly. It may weaken the blood thinner warfarin, but the proof is thin.

When: Fat-soluble. Absorbs better with a meal that has fat.

Example: Sports Research CoQ10. brand site. Link checked, not paid.

Reliably corrects low folate or B12. Little proof of benefit when levels are already normal.

Trade-off: High folate can fix the anemia of a B12 shortfall while nerve damage continues. That is one reason the two are paired.

When: B vitamins are usually taken in the morning. No study compares timing.

Example: Sports Research 5-MTHF. brand site. Link checked, not paid.

Corrects low vitamin D reliably. A large US trial found daily vitamin D did not lower cancer or heart events.

Trade-off: High doses over time can raise blood calcium. The NIH fact sheet gives the adult upper limit.

When: Fat-soluble. Absorbs better with a meal that has fat.

Example: Sports Research D3 + K2. brand site. Link checked, not paid.

Lowers triglycerides reliably. Big heart trials are mixed.

Trade-off: A review of seven large trials linked it to more atrial fibrillation, an irregular heartbeat, especially at higher amounts.

When: Absorbs better with a meal that has fat.

Example: Sports Research Alaskan Omega-3. brand site. Link checked, not paid.