(R/S)-1,3-Butanediol dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
In people, it raises blood ketones for a few hours.
Evidence grade for (R/S)-1,3-Butanediol: Limited. The rule: people have taken it in a published study, but fewer than 100 of them. The sum on this page: 1 completed trial, none stating how many people. A grade counts how much has been done to people, not whether it works.
- People given it
- 0
- Human studies
- 1
- Found nothing
- 0
Dose
No human dose established
Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose.
1 completed trial, 0 people given it
2 effects reported, 2 unwanted, by people using it, not a trial
Goal pages: Fat loss and metabolism, Muscle and strength, Ageing and longevity, Heart and circulation
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
This is a small alcohol. Your liver turns it into a ketone, the fuel your body makes when you fast. So drinking it puts you in mild ketosis for a few hours. It is a food additive and is sold in some ketone drinks. It is not a drug.
What people take it for
- Ketosis without fasting or a keto diet.
- Better sports performance.
- A longer life, after a mouse study.
What studies in people showed
In 9 trained cyclists, it raised blood ketones. 5 of the 9 had moderate to bad gut problems. Their time trial was no faster. A related ester went down fine for 28 days in 59 healthy adults, but that is a different molecule. No study in people ran longer than 28 days. Now mice. The mice ate it as 10 percent of their food. Females gained 2 percent in typical lifespan, but only when one lab was counted. Males gained 9 percent, but only by a test that counts early deaths more. In another mouse study, it raised midlife deaths when started young.
What people report
Reports, not study results
The good
- We have not collected user reports on this one yet.
The bad
- Moderate to severe gut problems in 5 of 9 cyclists.
- Dizziness, nausea or a feeling of being high in 2 of the 9. It is an alcohol.
Where these come from: The side effects are from the cycling study on this page. We have no user reports.
My bottom line
It gets you ketones and a sore gut. It did not make anyone faster. The mouse results are the shakiest in the program, so I would not drink this to live longer.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals (R/S)-1,3-Butanediol has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Lasting longer, staminano headcount stated · 1 study
Animal and lab work, not yet tested in people
Real results, but from animals or cells, not people. What works in a mouse often does not work the same way in a person. Nobody can patent this, so nobody would ever earn back the cost of a study in people. That is usually why there is none. The record on this one is set out below.
- Feeling less hungry1 animal or lab study
- Heart attacks and strokes1 animal or lab study
- Living longer1 animal or lab study
32 of the 36 indexed goals have no study of any kind behind (R/S)-1,3-Butanediol
No study in people, animals or cells on this page reports a result for these. That does not prove (R/S)-1,3-Butanediol does nothing for them. It does mean anything you have heard about (R/S)-1,3-Butanediol and one of these did not come from a study cited here.
Show full evidence
What is (R/S)-1,3-Butanediol?
In people, it raises blood ketones for a few hours. In 9 cyclists, it gave 5 of them moderate to severe gut problems and did not make them faster. In mice, it gave the NIA lifespan program's most shaky result. Females gained 2 percent in typical lifespan, but only when one lab was counted. Males gained 9 percent, but only by a test that counts early deaths more. The mice ate it as 10 percent of their food by weight.
1,3-butanediol is a small alcohol. The liver turns it into beta-hydroxybutyrate (BHB), a ketone. So drinking it puts you into mild ketosis without fasting or a keto diet. It is an approved food additive solvent. It is the base of several ketone ester drinks, and it is sold on its own in some ketone supplements. It is here because the NIA mouse lifespan program tested it. Also, the ketone it makes has a big, mixed record on lifespan in animals.
In people, the published record is short-term and about metabolism. In 9 trained male cyclists, each rider tried 1,3-butanediol and a dummy drink, in turn. They took 0.35 g/kg of the standard mixed form before and during 85 minutes of steady riding. Blood ketones rose to 0.44 to 0.79 mmol/L during exercise, against 0.11 to 0.16 on the dummy drink, and to 1.38 mmol/L an hour later. It raised oxygen use early in exercise. 5 of the 9 had moderate to severe gut problems. 2 had dizziness, nausea or a high. Time trial times did not change (28.7 against 28.5 minutes), and neither did power. Esters built from the (R) form of 1,3-butanediol have more data. In a 28 day study of a bis-hexanoyl ester, 59 healthy adults took 12.5 then 25 g a day. They handled it as well as people on a dummy drink, and safety blood tests did not change. Other studies show blood ketones rising to 0.8 to 1.7 mM for a few hours. Those esters are different molecules that release 1,3-butanediol in the gut. So they speak to its safety at gram doses, but not to the mixed form itself. No human study has run longer than 28 days or looked at ageing.
In mice, the NIA lifespan program mixed the standard mixed form into food at 100,000 ppm, which is 10 percent of the food by weight, from 6 months of age in the 2017 run. Pooled across three labs, typical (median) female lifespan was 2 percent higher. Most of that came from two labs (7 percent at The Jackson Laboratory, 4 percent at UT). The authors say the female result held only if they counted the lab where untreated mice died unusually young. Survival to old age did not change. Males gained 9 percent at the median, but the standard test said that could be chance. The 2024 second look with the Gehan test flipped the picture. The male result held up, and the female result no longer did. The second-look authors group it with compounds whose benefit is limited to midlife. A separate 2023 study in Aging Cell found something else. A 1,3-butanediol diet started early in life raised midlife deaths in normal mice. Started in old mice, it extended lifespan. It also prevented early deaths in mice missing a key ketone-making enzyme (HMGCS2).
1,3-butanediol is not a drug. It is allowed as a food additive and sold in supplements. It is not approved to treat anything.
How does (R/S)-1,3-Butanediol work?
The liver breaks down 1,3-butanediol, the same way it breaks down alcohol, into BHB, the main ketone in the blood. The (R) form of the molecule makes the natural D form of BHB. The (S) form makes the L form, which the body handles differently and which is less studied. The mixed form the mouse program used makes both. In people, one dose raises D-BHB to about 0.5 to 1.5 mmol/L for a few hours. It lowers blood sugar and free fatty acids. At gram doses it often upsets the gut. Since it is an alcohol, some people also feel mildly drunk. The case for longevity is that BHB is a signal as well as a fuel. In rodents and in a dish, it blocks enzymes that pack away genes (class I HDACs), calms an inflammation switch (NLRP3), and changes gene activity in ways that overlap with eating less. Animal studies disagree on whether taking ketones from outside, day after day, does what the body's own ketones do. The same 1,3-butanediol diet shortened or lengthened mouse life depending on the age it started.
What have studies in people found about (R/S)-1,3-Butanediol?
Short-term studies of metabolism and how well people handle it. The mixed form itself has one published study, in 9 cyclists who each tried it and a dummy drink. Esters of the (R) form have trials of up to 28 days in about 60 healthy adults. Nothing longer, nothing in older adults, nothing on ageing.
- 59 healthy adults, 28 days, an ester of the (R) form at up to 25 g a day: they handled it as well as people on a dummy drink, and safety blood tests did not change. The maker paid for it, and it is a different molecule.
- 18 adults, an ester of the (R) form, each tried it and a comparison drink in turn: no change in two fat-tissue hormones, asprosin and leptin, over 150 minutes.
- 9 trained male cyclists, 0.35 g/kg of the mixed form, each tried it and a dummy drink in turn: ketones rose to 0.44 to 1.38 mmol/L. 5 of 9 had moderate to severe gut problems. No change in time trial time or power.
- 8 healthy adults, how an ester is absorbed: R-BHB stayed at 0.8 to 1.7 mM for up to five hours. Blood sugar and free fatty acids fell. A small amount of the non-natural S form showed up.
- No study has given 1,3-butanediol or its esters to people for longer than 28 days, to older adults in particular, or looked at anything to do with ageing.
What this does not tell you: The human data show that 1,3-butanediol raises blood ketones for a few hours. They show the mixed form, at athlete doses, upsets the gut in most people. They say nothing about years of use or about what the (S) form does. They do not show whether ketones from a drink do in a person what the body's own ketones are thought to do. The mouse program's mice ate 10 percent of their food as 1,3-butanediol for life. No person eats anything like that.
The state of the research
The National Institute on Aging runs a mouse lifespan program called the Interventions Testing Program. It tests each compound at three labs at the same time: The Jackson Laboratory, the University of Michigan and UT Health San Antonio. The mice are a mixed breed, so a result is less likely to be a quirk of one strain. Males and females are both tested and judged separately. The three labs' results are then pooled. Every result gets published, whether or not the compound worked. It runs on public money from the National Institute on Aging, with no drug company money. In the 2017 run, 1,3-butanediol gave the program's most shaky result. The 2 percent gain in typical (median) female lifespan passed the standard test. But the authors write that it showed up only when they counted the lab whose untreated females died unusually young. Survival to old age did not move. The 9 percent gain in typical male lifespan did not pass the standard test.
Some results on these pages are called "Gehan-only". That is a weaker claim than "made mice live longer", so it needs explaining. The program's standard test counts every death the same. In 2024 a group at UT Health San Antonio went back over all the program's survival data from 2004 to 2022. That covered 132 compound and sex pairs. They used a second test, called the Gehan test. It gives more weight to deaths that happen young and in midlife. Five compounds that failed the standard test passed this one: metformin, enalapril and 17-DMAG in males, and CAPE and green tea extract in females. The authors say this is the pattern you would expect from something that stops mice dying young and then stops helping. In their words, the effects are "limited to midlife and may not be effective at older ages". They did not report any adjustment for running so many tests at once. So a Gehan-only result means fewer mice died young. By old age the groups caught up, and the oldest mice lived no longer.
For 1,3-butanediol the second look swapped the sexes. The male result passed the Gehan test, and the female result no longer passed. When the sex that benefits changes depending on which test and which labs you use, the effect is not solid. The second-look authors group it with compounds whose benefit is limited to midlife. The wider animal record adds a warning, not support. The 2023 Aging Cell study found the same kind of diet raised midlife deaths in normal mice when started young, and extended life when started old. Nobody pays for long human trials of a cheap bulk chemical. So what years of taking ketones does to a person is an open question, both ways.
The evidence, in charts
Fig. 1a · how many people
3studies in people cited, but none says how many people took part
number of people not stated
We do not draw a total, because none of the studies in people on this page gives one. Read the sources below for what each study measured.
We read the number of people from the source lines on this page. Where a line gives no number, we count nothing for it. We do not guess.
Fig. 1b · evidence mix
3 of 6 sources here are studies in people. The rest are not.
- Study in people · done in people350%
- Animal study · done in animals350%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
The studies cover 5 different years, 2019 to 2024, counted from the list of sources on this page.
Fig. 3 · legal status at a glance
US
Not approved
UK
Not approved
AU
Not approved
CA
Not approved
Not approved in any of the four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 4 · how much does what
Nobody has tested different amounts in people
This chart would show how the effect changes as the amount goes up. For this compound, nobody has measured that in people. So we leave it empty. We will not borrow an animal chart and pretend it works the same in people.
Fig. 5 · what the molecule is
- Kind of compound
- Supplement
- Molecule weight
- Not on file
- Half-life
- None on file
- Chain length
- None on file
No amino acid sequence is on file for (R/S)-1,3-Butanediol, which is expected: a supplement is not built from amino acids.
The studies we cite
- Study in people2019The effect of 1,3-butanediol on cycling time-trial performance
It raised ketones in the blood, made people feel ill, and did not make them faster. Nine trained male cyclists took either 1,3-butanediol or a dummy drink before and during 85 minutes of steady riding, then a time trial. Each rider did both, in turn. Blood ketones rose several times over, so the compound does what it should chemically. Five of the nine had moderate to severe stomach and bowel problems. Time trial results came out the same either way.
Randomised crossover, 9 trained male cyclists, 0.35 g/kg racemic 1,3-butanediol or placebo before and during 85 minutes of steady exercise then a time trial. Blood D-beta-hydroxybutyrate 0.44 to 0.79 mmol/L during exercise (placebo 0.11 to 0.16), peak 1.38 mmol/L after. Moderate to severe gastrointestinal symptoms in 5 of 9; dizziness, nausea or euphoria in 2. Time trial 28.7 versus 28.5 minutes, p = 0.62; power 286 versus 290 W, p = 0.50. No performance benefit. Academic study.
- Study in people2021Tolerability and safety of a novel ketogenic ester, bis-hexanoyl (R)-1,3-butanediol: a randomized controlled trial in healthy adults
A different molecule, and it went down easily for a month. 59 healthy adults took a bis-hexanoyl ester, 12.5 grams a day for a week and then 25 grams a day, or a dummy drink that tasted the same, for 28 days. Nobody knew which they had. Stomach complaints were no different between the groups, and safety blood tests showed nothing that mattered. Ketones rose after each dose. The maker paid for it. This is a related ester, not the mixed form sold as a supplement.
59 healthy adults, 28 days, double-blind, 12.5 g a day for a week then 25 g a day of a (R)-1,3-butanediol diester or taste-matched placebo. No difference in gastrointestinal or systemic tolerability scores, no clinically meaningful changes in vital signs or laboratory safety measures; blood ketones rose after each dose. Manufacturer funded; a related molecule, not the racemate.
This study gave people bis-hexanoyl (R)-1,3-butanediol diester, not (R/S)-1,3-Butanediol. It is here because it belongs on the record, and it is excluded from every count on this page.
- Study in people2023Bis hexanoyl (R)-1,3-butanediol, a novel ketogenic ester, acutely increases circulating R- and S-beta-hydroxybutyrate concentrations in healthy adults
This measures what the ester does to blood ketones, and nothing more. Eight healthy adults tried three different set-ups, in an order picked by chance. Blood levels of the natural ketone rose and stayed up for as long as five hours, more at higher doses. A non-natural mirror form also showed up, at far lower levels. Blood sugar and free fatty acids fell. Eight people, no health result, and again the ester, not the mixed form sold as a supplement. The maker paid for it.
8 healthy adults, three randomised crossover conditions. Plasma R-beta-hydroxybutyrate rose to 0.8 to 1.7 mM for up to five hours, dose dependent; the non-physiological S form rose to 20 to 60 microM; glucose and free fatty acids fell. Kinetics of the ester, not the racemate. Manufacturer funded.
This study gave people bis-hexanoyl (R)-1,3-butanediol ester, not (R/S)-1,3-Butanediol. It is here because it belongs on the record, and it is excluded from every count on this page.
- Animal study2022Lifespan benefits for the combination of rapamycin plus acarbose and for captopril in genetically heterogeneous mice
In mice. The 2017 run of the NIA mouse lifespan program fed 1,3-butanediol at 100,000 ppm from 6 months. Females (134 treated, 276 untreated): typical lifespan up 2 percent, mostly from two labs. It only held if the lab with unusually short-lived untreated mice was counted. Survival to old age did not clearly change. Males (145 treated, 285 untreated): typical lifespan up 9 percent, which the standard test said could be chance. Public NIA money paid for it.
ITP 2017 cohort. (R/S)-1,3-butanediol at 100,000 ppm in chow from 6 months. Females (134 treated, 276 controls): median +2 percent, p = 0.04 pooled, driven by two sites (+7 percent TJL, +4 percent UT), and dependent on including the site with unusually short-lived controls; 90th percentile +4 percent, not significant. Males (145 treated, 285 controls): median +9 percent, log-rank p = 0.11, not significant. NIA funded.
- Animal study2024The Gehan test identifies life-extending compounds overlooked by the log-rank test in the NIA Interventions Testing Program: metformin, enalapril, caffeic acid phenethyl ester, green tea extract, and 17-DMAG
In mice. A second look at the NIA mouse lifespan program. For 1,3-butanediol, typical male lifespan rose 9 percent. The standard test said that could be chance, but the Gehan test, which counts early deaths more, said it held up. The female gain that passed the standard test did not pass the Gehan test. The authors group it with compounds whose benefit is limited to midlife. Public NIA money paid for it.
1,3-butanediol males: median +9 percent, log-rank p = 0.11, Gehan p = 0.025, proportional hazards not violated. The female effect that was significant by log-rank was not significant by Gehan. Grouped by the authors with compounds whose benefit is limited to midlife. NIA funded.
- Animal study2023Ketone bodies: a double-edged sword for mammalian life span
In mice. Mice missing a key ketone-making enzyme (HMGCS2) died early, and a 1,3-butanediol diet prevented that. In normal mice, the same diet started early in life raised midlife deaths. Started in old mice, it extended lifespan. It also prevented deaths from clogged arteries in mice bred to get them (ApoE-deficient). A keto diet with no limit on food sharply raised deaths. An independent Japanese group did the work.
Mice lacking the ketogenesis enzyme HMGCS2 died early, which a 1,3-butanediol diet prevented. In normal mice the same diet started early in life increased midlife mortality, while started in aged mice it extended lifespan and prevented atherosclerosis deaths in ApoE-deficient mice. An ad libitum ketogenic diet markedly increased mortality. Independent Japanese group.
Common questions
Has (R/S)-1,3-Butanediol been tested in people?
Yes. 0 people given it across 1 completed trial cited here, 0 of which found nothing. In people, it raises blood ketones for a few hours.
What is the (R/S)-1,3-Butanediol dosage?
No human dose established. Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose. 1 completed trial, 0 people given it
Is (R/S)-1,3-Butanediol FDA-approved?
Not a drug. Allowed in US food as a liquid that carries flavourings. Sold in ketone supplement products. Not approved for any use. The lifespan result from the Interventions Testing Program (ITP), a US government-funded mouse study, is unclear. Females lived 2 percent longer by the standard test, but only at some test sites. Males lived 9 percent longer, but only by one other test (the Gehan test). The mice got it as 10 percent of their diet.
Did 1,3-butanediol extend lifespan in the ITP?
Shakily. Females gained 2 percent in typical lifespan, but the authors say that depended on counting one lab where untreated mice died unusually young, and survival to old age did not change. Males gained 9 percent, which failed the program's standard test. A 2024 second look with the Gehan test said the male gain held up, and at the same time the female result stopped holding up. The dose was 10 percent of the food by weight.
What does it do in people?
It raises blood BHB, a ketone, to about 0.5 to 1.5 mmol/L for a few hours. In the one study of the mixed form, 0.35 g/kg gave 5 of 9 cyclists moderate to severe gut problems and did not help performance. Esters of the (R) form went down fine at 25 g a day for 28 days in 59 healthy adults, in a study the maker paid for. No human study has looked at ageing.
Is 1,3-butanediol the same as a ketone ester?
No. Store-bought ketone esters are the (R) form of 1,3-butanediol chemically joined to BHB or to fatty acids. They release the (R) form when digested. The mouse program fed the free mixed-form alcohol. Its (S) half also makes the L form of BHB. The human safety data on esters tell us something about 1,3-butanediol, but they are not data on the mixed form.
Do ketones extend lifespan?
In mice, it depends on timing. A 2023 study found a 1,3-butanediol diet raised midlife deaths when started young, and extended life when started old. A keto diet with no limit on food raised deaths. No human data answer the question.