When the trials gave each supplement.
This page reports what the cited trials did: the time of day, and whether doses went with food, wherever the trial report says. Where it does not say, this page says that too. It is a record of the research, not a schedule, and not medical advice.
109 supplements. Each entry is also shown on that supplement's own page, with a note on whether the full paper or only its published summary was read.
In the morning (8)
The cited trials gave it in the morning.
In the cited immune-response trial, astaxanthin was taken as one softgel every morning (PMID PubMed ID: the permanent number the US National Library of Medicine gives a published paper. Each one links to that paper's record on PubMed. 20205737). The skin trial summary gives 6 mg a day without a time (PMID 22428137). Neither report says it was taken with a meal.
In the cited blood pressure trial, the daily 250 mL juice was taken at the same time each morning (PMID 25421976).
In the cited trial, a combination of palmitoylethanolamide and luteolin was taken once daily, 5 to 10 minutes before breakfast (PMID 35450527).
In the cited vascular trial, capsules were taken once each morning with breakfast (PMID 29661838). In the cited exercise trial, one tablet was taken 30 minutes before breakfast (PMID 35623315).
In the cited 8-week trial, one capsule was taken each morning (PMID 27785095). The summaries of the other cited trials do not state a time (PMID 18971533, PMID 33843667).
In the 60-day trial in healthy middle-aged adults, NMN was taken once daily before breakfast, with water (PMID 36482258). The 10-week trial in postmenopausal women gave 250 mg a day, and its report does not state a time (PMID 33888596).
In the cited 12-week trial, two 100 mg capsules were taken each morning (PMID 39069269). The summary of the other cited trial does not state a time (PMID 38035997).
In the cited study, two capsules were taken each morning (PMID 37849591). The report does not say whether they were taken with food.
In the evening or at bedtime (1)
The cited trial gave it in the evening or before bed.
In the cited trial, 3 g was taken 30 minutes before bedtime on each of three nights (PMID 22529837).
With or after meals (8)
The cited trials gave it with, before or after meals.
In the cited trial of a multi-strain product containing Akkermansia, three capsules were taken twice a day within 30 minutes of the morning and evening meals (PMID 32675291). The cited 3-month Akkermansia trial gave a daily dose and does not state a time (PMID 31263284).
The one cited human study tested a multi-ingredient formula that includes apigenin, taken as three capsules with breakfast and three with lunch (PMID 38302501). The other cited studies were laboratory and mouse studies (PMID 21641214, PMID 23172919).
In the cited trial, one capsule was taken twice a day, 30 minutes after breakfast and 30 minutes after dinner (PMID 39875757).
In the larger knee osteoarthritis trial, participants took two capsules after meals, three times a day (PMID 24672232). The other cited trial summaries do not state timing.
In the cited trial, a 300 mg capsule was taken before breakfast and before dinner (PMID 28459647).
The 12-month knee trial gave 200 mg once a day (PMID 23226979) and the skin trials gave 120 mg daily (PMID 34203487, PMID 41422283); the summaries do not state a time of day or whether doses were taken with food.
In the cited Japanese trial, three capsules were taken after each meal (PMID 21103034). The 1991 trial gave 100 mg three times a day (PMID 2027477). The summary of the 1993 trial does not state a time (PMID 8323999).
In the 900 mg trial, the two daily capsules were taken at breakfast and at supper (PMID 23340963). The summaries of the 250 mg trials give one dose a day without a time (PMID 23378458, PMID 28606567).
Split between morning and evening (5)
The cited trials divided the day's amount between morning and evening.
Both randomized trials gave 2-HOBA at fixed intervals: every eight hours in healthy volunteers (PMID 31907026) and three times daily around atrial fibrillation ablation (PMID 40709466). Neither report ties dosing to meals.
In the cited trial of an enzyme combination containing bromelain, three tablets were taken in the morning and three in the evening, at least 30 minutes before or 90 minutes after a meal (PMID 40803821).
In the cited 14-day trial in healthy older adults, each day's amount was split into a morning and an evening dose (PMID 35821844). The other cited trial reports do not state a time (PMID 35975308, PMID 33783984).
In the cited exercise trial, 200 mL was taken in the morning and 200 mL in the evening (PMID 36011907). In the sleep trials the juice was taken morning and evening (PMID 22038497) or one hour before bed (PMID 39683518).
No cited study gave NAD+ Nicotinamide adenine dinucleotide, a molecule cells use in energy metabolism. Its level falls with age in some tissues. itself by mouth. In the cited NMN study, 125 mg was taken in the morning and 125 mg in the evening (PMID 35479740). In the cited NR study, a single 900 mg dose was taken at 5 a.m., four hours before a brain scan (PMID 39044608).
Around training (2)
The cited trials tied the dose to exercise sessions.
In the cited collagen-synthesis study, vitamin C-enriched gelatin was taken one hour before a short bout of exercise (PMID 27852613); that is a different preparation. The summaries of the joint-pain trials do not state a time (PMID 18416885, PMID 28177710, PMID 37551682).
In the trials pooled for strength in older adults, creatine was taken within 60 minutes after exercise (PMID 34199420). In the 2-year bone trial, half the dose was taken just after training and half with a meal, and on rest days it was split across meals (PMID 37144634). The depression trial report gives 3 g a day for the first week and 5 g a day after that, without a time (PMID 22864465).
One dose before a test (2)
The cited trial gave a single dose before a test, not a daily schedule.
In the cited trial, a single 2,000 mg dose was taken before a stress and cognitive challenge (PMID 38975711). It was not a daily schedule.
In Telch 2014, capsules were taken around therapy sessions: one after the session, one at bedtime that night and one on waking (PMID 25018057). In Rodriguez 2016 a single dose was given one hour before testing (PMID 27351678). Neither was a daily schedule.
Timing differed between trials (5)
The cited trials did not agree on a time, so each is listed.
Timing differed between the cited trials: one capsule once daily after dinner (PMID 31517876), one capsule twice a day after food (PMID 23439798), and one capsule on waking and one shortly before bed (PMID 26609282).
The glucose trials gave a single dose shortly before a meal or glucose drink, or 15 minutes before each meal for 14 days (PMID 38483543, PMID 33367782). The heart failure trials split the daily amount into four doses (PMID 39162035).
Timing differed between the cited studies. In the 12-week trial in older adults with mild cognitive impairment, 500 mg was taken in the morning and 500 mg in the evening (PMID 42478598). In the obese-men trial, 1,000 mg was taken twice daily (PMID 29992272). The first human study gave single morning doses after an overnight fast (PMID 27721479). The NR plus pterostilbene combination trial dosed at breakfast (PMID 29184669).
The cited studies gave sermorelin by injection under the skin: twice daily in one (PMID 1379256) and once nightly in another (PMID 9005976).
Timing differed between the cited trials. In two, the daily dose was taken in the morning on an empty stomach, with water (PMID 35584623, PMID 35050355). In a third, it was split, with one capsule after breakfast and one after dinner (PMID 39487653).
Dose reported, timing not reported (71)
The cited reports give how much and how often, but not the time of day or whether it was taken with food.
The cited trial gave 100 mg twice daily (PMID 35940251). Its summary does not state a time of day or whether doses were taken with food.
One cited trial gave doses three times a day (PMID 15616239), and the cited reviews pool trials without reporting when doses were taken (PMID 12598816, PMID 32408706). None states a time of day or whether doses were taken with food.
The SYDNEY 2 trial gave one oral dose a day (PMID 17065669), and the other cited trial gave 300 mg a day (PMID 21666939). Neither summary states a time of day or whether it was taken with food.
The cited Alzheimer's trial gave 400 mg capsules three times a day (PMID 12637119). Its summary does not state a time of day or whether doses were taken with meals.
The cited trial gave one capsule twice daily (PMID 31060549). Its report does not state a time of day or whether doses were taken with food.
In the cited six-person report the supplement was taken daily (PMID 38404609). The summary does not state a time of day or whether it was taken with a meal. The other cited study was in mice (PMID 36332287).
The cited 12-month trial gave 300 mg twice a day (PMID 41571333). Its report does not state a time of day or whether doses were taken with food.
The cited diabetes trial gave 1.0 g a day (PMID 18397984). Its summary does not state how the dose was split or whether it was taken with meals.
The cited reviews pool trials using about 5 g a day and do not report a time of day or whether doses were taken with food (PMID 27797728, PMID 22270875).
The cited trials gave beta-carotene daily (PMID 8127329, PMID 15572756). Their summaries do not state a time of day or whether it was taken with food.
The summary of the cited 12-week trial does not state a time of day or whether doses were taken with food (PMID 32951763).
The cited review does not report when doses were taken (PMID 32540741).
The cited reviews pool trials and do not report when doses were taken (PMID 32680575, PMID 29018060).
The cited review pools trials and does not report when doses were taken (PMID 38361147).
The cited trial gave 2 g a day (PMID 39770949). Its report does not state a time of day or whether doses were taken with food.
The summary of the cited pregnancy trial does not state a time of day or whether choline was taken with food (PMID 29217669).
The cited reviews pool trials and do not report when doses were taken (PMID 38581640, PMID 30575881).
The cited review pools trials and does not report when doses were taken (PMID 24635480).
The cited reviews pool trials and do not report when doses were taken (PMID 24019277, PMID 38917435).
The cited trials gave citicoline as 500 mg twice a day (PMID 12865605) or 1,000 mg/day (PMID 8624220); their summaries do not state a time of day or whether doses were taken with food. The cited review does not report when doses were taken (PMID 15846601).
Q-SYMBIO gave 100 mg three times daily (PMID 25282031), and the Naples trial gave 2 mg per kilogram of body weight a day (PMID 8241697). Neither summary states a time of day or whether doses were taken with meals.
The cited trial gave 3 g a day for 5 weeks (PMID 15118196). Its summary does not state a time of day or whether it was taken with food.
The cited trial gave DIM twice daily (PMID 28560655). Its report does not state a time of day or whether doses were taken with food.
In the cited trials DMSO was applied to the skin, three to five times a day depending on the trial (PMID 8194818, PMID 12670672). No trial tied it to a time of day.
The cited reviews pool tea and catechin trials and do not report when doses were taken (PMID 23780706, PMID 21715508); the 12-month extract trial gave four capsules daily without a stated time (PMID 27806972).
The cited trial gave 25 mg three times a week for a year (PMID 39544014); its summary does not state a time of day or whether doses were taken with food. The observational Research that watches what people already do rather than assigning a treatment. It can show that two things travel together, not that one causes the other. studies measured ergothioneine already in people's blood (PMID 27444382, PMID 36139790, PMID 34673145).
The cited review pools trials and does not report when doses were taken (PMID 36837450).
The cited trials gave folic acid daily (PMID 25771069, PMID 17551129). Their summaries do not state a time of day or whether it was taken with food.
The cited trial gave 1,000 mg a day (PMID 39645105). Its summary does not state a time of day or whether it was taken with food.
The cited trial gave 200 mg once daily (PMID 38321713). Its summary does not state a time of day.
The cited reviews pool trials of the extract and do not report when doses were taken (PMID 32658034, PMID 39895346).
The cited trial gave 1,500 mg a day (PMID 16495392). Its summary does not state a time of day or whether it was taken with food.
The cited 6-month trial gave 250 or 1,000 mg a day (PMID 24791752). Its summary does not state a time of day or whether doses were taken with food.
The trial behind the VCAM-1 pool gave hesperidin 2S once daily for 6 weeks (PMID 27797708) and the 2026 vascular trial gave 210 mg/day in a beverage (PMID 42605853); neither summary states a time of day. The pooled analyses do not report timing (PMID 30991044).
The trials gave HMB daily, in most cases 3 g of calcium HMB (PMID 30859862) or 1.5 g (PMID 34081113), without a stated time of day; the pooled analyses do not report timing (PMID 40248035, PMID 41934514).
The cited reviews pool trials and do not report when doses were taken (PMID 36703143, PMID 35477841).
The blood flow study gave 6 g/day for 14 days without a stated time (PMID 28940638); the blood pressure pool does not report timing (PMID 30788274); the citrulline malate performance studies gave 6 to 8 g 40 to 60 minutes before exercise (PMID 30895562).
In the cited 12-week trial, two tablets a day were held in the mouth for a few tens of seconds and then swallowed (PMID 37764743). The report does not state a time of day.
The 2009 trial gave four 250 mg tablets three times a day (PMID 18844328). Its summary does not state a time of day or whether the tablets were taken with meals.
The microdose trial gave lithium once daily (PMID 22746245), and the other cited trial gave it daily (PMID 21525519). Neither summary states a time of day or whether it was taken with food.
In the insomnia trial, magnesium oxide was given as one tablet twice a day (PMID 23853635). The report does not say at what time of day. The insomnia meta-analysis A study that pools the numbers from several trials into one combined estimate. describes doses taken two to three times a day (PMID 33865376).
The 2013 meta-analysis report (Ferracioli-Oda et al., PLoS One, 2013; PMID 23691095) and the summaries of the other two cited reviews (Brzezinski et al., Sleep Med Rev, 2005; PMID 15649737, Chen et al., Mol Neurobiol, 2016; PMID 26189834) give doses and durations but not the time of administration.
The cited reviews pool trials, most dosing two or three times a day, and do not report a time of day or whether doses were taken with food (PMID 38579127, PMID 29245314, PMID 40552569). The two biopsy trials dosed three times daily (PMID 31536511, PMID 28419855).
The schizophrenia trials gave 1 g twice daily (PMID 18436195, PMID 35857752) and the COPD trials 600 mg twice daily (PMID 24621680, PMID 23348146); none states a time of day or a relation to food. The GlyNAC trial summary does not state timing (PMID 35975308).
The summaries of the cited trials do not state when the extended-release niacin was taken (PMID 25014686, PMID 22085343).
REDUCE-IT gave 2 g of icosapent ethyl twice daily (PMID 30415628). GISSI-Prevenzione, ASCEND and VITAL gave 1 g a day (PMID 10465168, PMID 30146932, PMID 30415637). The VITAL report does not state a time of day or whether capsules were taken with food, and the summaries of the other three do not either.
The cited reviews pool trials of the formula and do not report when doses were taken (PMID 27021597, PMID 16600251).
The cited review pools trials and does not report when ginseng doses were taken (PMID 33871063).
The cited prostate cancer studies gave daily doses (PMID 14663471, PMID 34959847). They do not state a time of day or whether doses were taken with food.
The cited studies gave PQQ once daily (PMID 27526146) or as a drink dosed by body weight (PMID 24231099). Neither summary states a time of day or whether it was taken with food.
In the cited antibiotic trials the probiotic was given once a day (Allen et al., Lancet, 2013; PMID 23932219), twice a day (Hickson et al., BMJ, 2007; PMID 17604300), or as one or two capsules a day (Gao et al., Am J Gastroenterol, 2010; PMID 20145608), alongside antibiotic treatment. The summaries do not state whether doses were taken with meals.
The cited trial gave pterostilbene twice daily (PMID 25057276). Its report does not state a time of day or whether doses were taken with meals.
The summaries of the cited meta-analyses on blood pressure, lipids and glucose do not state the time of administration (PMID 27405810, PMID 31940027, PMID 25897620, PMID 30848564). None of the cited studies tested an on-off senolytic A compound intended to clear senescent cells: older cells that have stopped dividing but remain in tissue. schedule.
The cited trials gave the extract daily (PMID 18549841, PMID 19602720). Their summaries do not state a time of day or whether it was taken with food.
The cited review does not report when doses were taken (PMID 27045603).
The cited 30-day trial gave 150 mg a day (PMID 22055504). Its report does not state a regular time of day or whether doses were taken with food.
The cited trials gave a standardized extract daily (PMID 12725561, PMID 11081987, PMID 10839209, PMID 19016404). They do not state a time of day or whether doses were taken with food.
The cited reviews pool trials and do not report when doses were taken (PMID 30036891, PMID 38913392).
The cited trials gave daily doses (PMID 24500245, PMID 31712971). They do not state a time of day or whether doses were taken with food.
The cited trials gave a daily dose (PMID 8971064, PMID 19066370, PMID 22626835, PMID 17620655). They do not state a time of day or whether doses were taken with food.
In the cited dental surgery trial, 10 mg was taken three times daily after the operation (PMID 33653320). The report does not tie the doses to meals or times of day.
The cited trials gave sulforaphane or broccoli sprout powder daily (PMID 22537070, PMID 21559038, PMID 27832073, PMID 25313065). They do not state a time of day or whether doses were taken with food.
In the type 2 diabetes trial, taurine was given as 1 g three times a day (PMID 35870947); the report does not state whether doses were taken with meals. In the running trial, a single dose was taken about 2 hours before the run (PMID 22855206).
The betaine trial summary gives daily doses (PMID 14652361), and the betaine-with-B-vitamins trial gave four tablets a day (PMID 36717385). Neither states a time of day or whether doses were taken with food.
The summary of the cited 6-month trial does not state a time of day or whether doses were taken with food (PMID 33541567).
The oral trial in healthy adults gave 100 g/day, and its report does not state a time of day or whether it was taken with food (PMID 27208415). Two other cited trials gave trehalose intravenously once a week (PMID 35045351, PMID 40409314).
The cited review does not report when doses were taken (PMID 36445793).
VITAL gave 2,000 IU of vitamin D3 a day (PMID 30415629). Its report does not state a time of day or whether the capsule was taken with food, and the other trial summaries cited on this record do not either.
The cited trials gave vitamin E daily (PMID 21990298, PMID 8127329, PMID 15769967) or every other day (PMID 19066368, PMID 15998891). They do not state a time of day or whether doses were taken with food.
The two MK-7 trials gave 180 µg a day (PMID 25694037) and 360 µg a day (PMID 42268593). Neither summary states a time of day or whether it was taken with food.
The trial of the 13 mg lozenge had it taken six times a day (PMID 31980506). The pooled analyses give daily amounts from lozenges taken through the day and do not state clock times (PMID 22566526, PMID 27378206).
No human trial timing (8)
The cited evidence is not a human supplement trial given by mouth on a schedule.
No oral human trial is cited. The cited human reports gave BPC-157 by injection or by intravenous infusion (PMID 34324435, PMID 40131143), not by mouth on a daily schedule.
The cited studies were done in rats and mice (PMID 22498298, PMID 33123847). There is no human trial timing on this record.
The cited evidence is a mouse study (PMID 32877690) and an observational study of people taking a commercial formula at two tablets a day, which does not state a time (PMID 34847066). There is no randomized human trial timing on this record.
The senolytic study was done in mice and in laboratory cell and tissue samples (PMID 30279143). The human trials in other uses gave fisetin daily (PMID 29541713, PMID 42218768) without a stated time; none is a trial of the graded use.
The cited studies were done in rats, mice and muscle cells (PMID 31491372, PMID 42323079, PMID 29951166). There is no human trial timing on this record.
The cited study was done in cell cultures (PMID 27913811). There is no human trial timing on this record.
The cited study was done in mice and cell cultures (PMID 34873338). There is no human trial timing on this record.
The cited evidence is a mouse study (PMID 27841876) and a study of dietary intake in people (PMID 29955838). Neither tested a supplement schedule, so there is no trial timing to report.
Absorption interactions in the studies
What absorption studies measured when these were taken together. Single-meal studies and whole-diet studies do not always agree, and both are shown.
In single-meal studies, adding 165 to 600 mg of calcium to a meal cut the iron absorbed from that meal by 50 to 60 percent, for both plant and meat iron (Hallberg et al., Am J Clin Nutr, 1991; PMID 1984335). Over a whole diet the result was different: when 14 people raised or lowered their calcium intake for 5 days at a time, between 280 and 1,281 mg a day, their iron absorption did not change (Reddy and Cook, Am J Clin Nutr, 1997; PMID 9174478). Calcium eaten at breakfast did not reduce iron absorption from a meal eaten 2 or 4 hours later (Gleerup et al., Eur J Clin Nutr, 1993; PMID 8156984).
Taken together in water on an empty stomach, a large excess of iron reduced zinc absorption: at 25 parts iron to 1 part zinc, absorption fell from 59 to 34 percent. Given with a meal, the same doses had no effect (Sandström et al., J Nutr, 1985; PMID 3973750). The reverse held for zinc on iron: a fivefold excess of zinc cut iron absorption by 56 percent in water, but not when given with a meal (Rossander-Hultén et al., Am J Clin Nutr, 1991; PMID 2058577).
In a metabolic study of five men, raising total magnesium intake to about 800 mg a day with magnesium oxide did not change how much calcium they absorbed, at either a low or a normal calcium intake (Spencer et al., J Am Coll Nutr, 1994; PMID 7836628). No study cited here measured the reverse, the effect of calcium supplements on magnesium absorption.
The FDA-approved prescribing information for Synthroid (levothyroxine), revised February 2024, directs that it be taken once daily on an empty stomach, half an hour to an hour before breakfast, and at least 4 hours apart from drugs known to interfere with its absorption; its interaction table names calcium carbonate, ferrous sulfate and magnesium-containing antacids. In 20 patients who took 1,200 mg of calcium a day as calcium carbonate with their levothyroxine for 3 months, thyroid hormone levels fell and TSH rose, and both returned when the calcium stopped (Singh et al., JAMA, 2000; PMID 10838651). In 14 patients who took a 300 mg ferrous sulfate tablet with their thyroxine for 12 weeks, average TSH rose from 1.6 to 5.4 (Campbell et al., Ann Intern Med, 1992; PMID 1443969). Swallowing levothyroxine with coffee lowered its absorption by 27 to 36 percent compared with water; coffee taken 60 minutes later did not (Benvenga et al., Thyroid, 2008; PMID 18341376).
Also: Synthroid (levothyroxine sodium) prescribing information, AbbVie, revised February 2024, sections 2.1, 7.1 and 7.9.