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Printed from https://bottledhope.co/supplements/spermidine/. Last reviewed 2026-09-26. Check the site for the latest version.

Spermidine

A natural compound in foods such as wheat germ, mushrooms, cheese and soybean products. It has been tested as a supplement for memory, hair and aging.

Explained simply · Last reviewed

What it is

Spermidine is a natural compound from a family called polyamines. The authors of a 2018 Italian study of diet and death describe it as the most abundant polyamine in most human tissues. They say the body's levels are influenced by food, gut bacteria and the body's own production, and they list wheat germ, broccoli, mushrooms, a variety of cheeses and soybean products such as natto among the foods rich in it. They also cite laboratory work in which giving spermidine was linked to longer survival in yeast, worms and flies, and to fewer age-related deaths in mice.

More about Spermidine

The authors of a 2018 Italian study of diet and death describe it as the most abundant polyamine in most human tissues. They say the body's levels are influenced by food, gut bacteria and the body's own production, and they list wheat germ, broccoli, mushrooms, a variety of cheeses and soybean products such as natto among the foods rich in it. They also cite laboratory work in which giving spermidine was linked to longer survival in yeast, worms and flies, and to fewer age-related deaths in mice.

The 12-month SmartAge memory trial and the vaccine pilot below tested a spermidine-rich extract of wheat germ, which both papers say came from a company called The Longevity Labs. The hair trial tested a spermidine-based supplement whose other contents its paper does not report. Whether the animal results carry over to people taking a supplement is what the ratings below are about.

Also known as: spermidine-rich wheat germ extract, polyamine

At a glance

Safety: known risks and 1 group who should avoid it or take extra care. See Safety ↓

Claims made about Spermidine, and how strong the evidence is for each:

Longevity and aging claims

Claims made about Spermidine and aging, and how strong the evidence is for each. A change in a marker is not the same as a longer life.

Each rating follows our published rules and the sources cited for it. We don’t add our own medical judgment. How we rate

Safety

Read this before the ratings below.

Risks

  • The safety evidence cited here comes from two small trials in older adults lasting up to a year, both using a spermidine-rich wheat germ extract. This page found no health-authority safety assessment of spermidine supplements.
  • In the 12-month SmartAge trial of 100 older adults, the authors report that adverse events and serious adverse events were balanced between the spermidine and placebo groups, and that every serious adverse event was rated as not related to the supplement. The authors describe the supplement as safe and well tolerated.
  • In the same trial, the one category with noticeably more adverse events on spermidine was muscle, bone and joint complaints (11 participants against 4 on placebo). The authors describe most of these as age-related conditions, such as osteoporosis, arthritis, gout attacks and joint pain.
  • The authors of the 12-month trial state that they chose a lower amount for their earlier pilot trial, and kept it in the 12-month trial, partly because their own earlier study in mice found an increase in relative kidney weight at a high amount. In their trial they report “inconspicuous kidney parameters”.
  • The authors of the 12-month trial note evidence from other research that polyamines, the family of compounds spermidine belongs to, may enhance tumor growth. Their trial excluded people with a previously diagnosed cancer, so it could not evaluate this.
  • A pilot trial in 40 adults over 65 reports that the supplement was well tolerated over 13 weeks.

Who should avoid it or take extra care

  • People with a current or past cancer diagnosis: the 12-month trial excluded them, and its authors state that the effect of spermidine supplements on tumor growth could not be evaluated. Separately, the authors of the Italian study of dietary spermidine and death from any cause wrote, in their published reply to a letter about their study, that “caution is warranted in patients with manifest cancer”.

Safety sources: Source [1]Source [2]Source [3]Source [4]Source [5]

What the evidence says

Each claim is rated on its own evidence. Ratings follow the scale on our methodology page.

  • Improves memory and thinking in older adults Evidence rating: Insufficient

    Older adults worried about their memory take it hoping it will keep their memory and thinking sharp.

    A 12-month trial in 100 older adults found no memory difference from placebo; a smaller study of bread rolls, with no placebo group, reported test scores rising in both of its groups.

    This page found no systematic review or health-authority assessment of this claim. The evidence is two small trials, and they point in different directions. The largest, the 12-month SmartAge trial, enrolled 100 older adults with self-reported memory worries. It found no significant difference from placebo in its main memory test or in any secondary measure. Its authors conclude that the supplement did not modify memory.

    The SmartAge authors report possible benefits on verbal memory in exploratory analyses that need confirming. They also report a worse result than placebo on one test of processing speed, which they say needs to be confirmed or refuted. They note that the supplement added only about 10% to participants’ usual daily spermidine, which may not have been enough. They add that their own earlier 3-month pilot in 30 people had found a memory improvement. The supplement’s maker supplied the SmartAge extract and funded work on developing it, and several SmartAge authors hold equity in that company.

    The second trial, in 85 care-home residents aged 60 to 96, compared bread rolls made with wheat germ (more spermidine) against rolls made with wheat bran (less spermidine), rather than a supplement against placebo. Overall test scores rose in both groups. The paper reports the larger gains within the higher-spermidine group, mainly in people with mild dementia.

    Under this site’s rules, when sources disagree the lower rating is taken. An insufficient rating means the evidence is too thin to show whether there is an effect; it does not mean the trials showed there is none.

    Sources: Source [1]Source [2]

  • Supports hair growth and reduces hair shedding Evidence rating: Insufficient

    People with thinning hair take it hoping it will help their hair grow and shed less.

    EFSA found in 2011 that spermidine had not been shown to contribute to normal hair growth; one later trial, funded by a company, reports less shedding and calls it preliminary.

    The European Food Safety Authority (EFSA) assessed a proposed claim that spermidine contributes to normal hair growth in 2011. It found that the two documents submitted, which described one trial, did not give enough information for a full scientific evaluation. It concluded that a cause-and-effect relationship between spermidine and normal hair growth had not been established.

    Later that year, EFSA considered an application from Giuliani S.p.A. to claim that spermidine prolongs the growing phase of the hair cycle. It did not rule on whether the effect was shown. It concluded that the claim, made for people with a form of chronic hair shedding (chronic telogen effluvium), related to the treatment of a disease, and so fell outside the rules for health claims on food. Giuliani submitted comments on that opinion; in 2012 EFSA responded that they did not change the Panel’s conclusion.

    A 2017 trial in 100 healthy adults was published after both opinions. It reports that a spermidine-based supplement taken for three months increased the share of hairs in the growing phase and reduced shedding compared with placebo. Its authors call the result preliminary.

    The trial was funded by Giuliani S.p.A., the applicant in the second EFSA opinion. Two of its four authors are employees of Giuliani, a third is a consultant to the company, and the fourth has received travel support from it. The paper does not report what the supplement contained besides spermidine.

    Sources: Source [1]Source [2]Source [3]Source [4]

Longevity and aging

What the cited sources report about lifespan, death from any cause, and markers studied in connection with aging. A change in a marker is not the same as a longer life. Each outcome is rated on its own evidence, on the same scale as the claims above.

  • Helps people live longer Evidence rating: Insufficient

    People take it hoping it will help them live longer.

    No cited study has measured lifespan in people; a 2016 study reports that spermidine in drinking water extended median lifespan in mice.

    No cited study has measured lifespan in people taking spermidine. The only lifespan evidence is from mice.

    A 2016 laboratory study reports that spermidine added to drinking water extended median lifespan in mice. Given life-long, it extended median lifespan in female mice. Started late in life, it extended median lifespan by about 10%. Several of the study’s authors hold equity in a company founded to develop natural food extracts.

    Sources: Source [1]

  • Lowers the risk of death from any cause Evidence rating: Insufficient

    People take it hoping it will lower their risk of dying early.

    Two studies of diet linked more spermidine from food with fewer deaths, and a third, in 29,079 Japanese adults, found no significant link; none of them studied supplements.

    No trial has tested whether spermidine supplements affect death from any cause. The evidence is three observational studies of spermidine from ordinary food, estimated from diet questionnaires, and they disagree.

    In an Italian cohort of 829 adults followed for 20 years, people who ate more spermidine were less likely to die from any cause. The authors report the same pattern in a second Austrian cohort. They state that their findings apply to spermidine from food and cannot readily be extrapolated to high-dose supplements. They add that bias from measurement error and other differences between people cannot be ruled out. Three of the authors hold equity in a company founded to develop natural food extracts.

    A published letter by Gostner and Fuchs did not dispute the association but argued that extra spermidine intake “is not without risk”. It cited animal studies and laboratory work on human immune cells suggesting that polyamines can suppress immune function. It warned that an excessive intake “may even promote adverse outcomes such as cancer development when critical immunoregulatory circuits are afflicted”.

    In their published reply, the study authors state that their finding of fewer cancer deaths among people eating more spermidine refers to spermidine naturally present in amounts typical of a Western or Mediterranean diet. They say it “allow[s] no conclusions on high-dose spermidine supplements or extreme diets”. Their view in the reply is that experimental and epidemiologic studies show “no convincing signal for tumor-promoting effects of moderate doses of spermidine”. They add that more research is required and that “caution is warranted in patients with manifest cancer”. Two of the reply’s authors hold equity in the same company.

    A study of 23,894 US adults also found a lower risk of death from any cause in those eating the most spermidine. A Japanese cohort of 29,079 adults followed for 16 years found no statistically significant association between spermidine intake and death from any cause in men or women. It found a suggestive link with more cancer deaths in women. Its authors conclude that their results do not support a benefit of dietary spermidine on mortality. Observational studies like these can show an association but cannot show that spermidine caused it. Under this site’s rules, when sources disagree the lower rating is taken.

    Sources: Source [1]Source [2]Source [3]Source [4]Source [5]

  • Improves blood markers of inflammation and immune-cell senescence Evidence rating: Insufficient

    Older adults take it hoping it will calm inflammation and keep their immune system working well as they age.

    A 12-month trial found no blood-marker difference from placebo; in a 40-person vaccine pilot, no immune effect was significant once the groups’ mix of men and women was allowed for.

    These are markers measured in blood, not lifespan or health outcomes. In the 12-month SmartAge trial of 100 older adults, spermidine made no significant difference compared with placebo to any blood marker measured, including markers of inflammation. Blood polyamine levels, the family spermidine belongs to, were not altered either; the authors add that blood levels may not reflect how much is taken in.

    In an exploratory analysis limited to participants who took nearly all their capsules, one marker of blood-vessel inflammation fell compared with placebo. The SmartAge authors say this needs to be confirmed. They add that none of their exploratory findings would be statistically significant after correcting for multiple testing.

    A 13-week pilot trial in 40 adults over 65, given the supplement after a COVID-19 booster, reports results that depend on the analysis. In unadjusted comparisons of the whole spermidine group with the placebo group, neutralizing-antibody activity after two weeks rose more on spermidine against 9 of the 10 virus variants tested. The paper’s text describes this result as a change from baseline, while its figure presents it as a comparison with placebo. The rise in anti-spike antibody levels was not statistically significant at any time point.

    In the analyses that allowed for the groups’ different mix of men and women, the pilot’s authors report that the treatment effect was not statistically significant for any immune outcome. The paper reports no differences between the spermidine and placebo groups in T-cell responses. The falls in immune-cell senescence markers and the largest antibody gains it highlights were in the people who had responded poorly to the vaccine. They were compared with those people’s own starting values and, in unadjusted comparisons, with the placebo group.

    The two arms were unbalanced on this: 8 of the 20 people on spermidine were poor responders, against 2 of the 18 on placebo. The pilot’s authors say these subgroup results should be interpreted with caution because of the small sample. The pilot was part-funded by the supplement’s maker, which also supplied the extract and placebo. Three of its authors disclose consultancies: two with the supplement’s maker, and two with another company, Oxford Healthspan (one author consults for both).

    Sources: Source [1]Source [2]

Which form the evidence used

Supplements are sold in several forms. This is what the sources on this page say about them — which form the research used, and any comparison those sources themselves made. Where they made none, this page does not rank the forms.

  • Spermidine-rich wheat germ extract, What the sources supportDetails

    The cited human trials of spermidine as a supplement for memory, safety and immune markers all used a spermidine-rich extract of wheat germ, made by The Longevity Labs. None of the cited sources compared this extract with any other spermidine product, so this page cannot say whether one form works better than another. Source [1]Source [2]

Sources

  1. Effects of Spermidine Supplementation on Cognition and Biomarkers in Older Adults With Subjective Cognitive Decline: A Randomized Clinical Trial
    JAMA Network Open, 2022 · Randomized controlled trial · Supporting source
    This source discloses industry funding.
    Some of its authors disclose ties to industry.
  2. The positive effect of spermidine in older adults suffering from dementia: First results of a 3-month trial
    Wiener klinische Wochenschrift, 2021 · Randomized controlled trial · Supporting source
  3. Scientific Opinion on the substantiation of health claims related to spermidine and contribution to normal hair growth (ID 1705) pursuant to Article 13(1) of Regulation (EC) No 1924/2006
    EFSA Panel on Dietetic Products, Nutrition and Allergies (EFSA Journal), 2011 · Health authority summary · Primary source
  4. Scientific Opinion on the substantiation of a health claim related to spermidine and prolongation of the growing phase (anagen) of the hair cycle pursuant to Article 13(5) of Regulation (EC) No 1924/2006
    EFSA Panel on Dietetic Products, Nutrition and Allergies (EFSA Journal), 2011 · Health authority summary · Primary source
  5. Response to comments on the Scientific Opinion on the substantiation of a health claim related to spermidine and prolongation of the growing phase (anagen) of the hair cycle pursuant to Article 13(5) of Regulation (EC) No 1924/2006
    European Food Safety Authority (EFSA Supporting Publications), 2012 · Health authority summary · Primary source
  6. A spermidine-based nutritional supplement prolongs the anagen phase of hair follicles in humans: a randomized, placebo-controlled, double-blind study
    Dermatology Practical & Conceptual, 2017 · Randomized controlled trial · Supporting source
    This source discloses industry funding.
    Some of its authors disclose ties to industry.
  7. Cardioprotection and lifespan extension by the natural polyamine spermidine
    Nature Medicine, 2016 · Animal or laboratory study · Supporting source
    Some of its authors disclose ties to industry.
  8. Higher spermidine intake is linked to lower mortality: a prospective population-based study
    The American Journal of Clinical Nutrition, 2018 · Observational study · Supporting source
    Some of its authors disclose ties to industry.
  9. The association of dietary spermidine with all-cause mortality and CVD mortality: The U.S. National Health and Nutrition Examination Survey, 2003 to 2014
    Frontiers in Public Health, 2022 · Observational study · Supporting source
  10. Dietary polyamine intake and all-cause and cause-specific mortality in Japanese adults in the Takayama study
    British Journal of Nutrition, 2024 · Observational study · Supporting source
  11. Cardioprotective effect of polyamine spermidine
    The American Journal of Clinical Nutrition, 2019 · Published comment · Not counted toward ratings
  12. Reply to Gostner and Fuchs
    The American Journal of Clinical Nutrition, 2019 · Published comment · Not counted toward ratings
    Some of its authors disclose ties to industry.
  13. Spermidine Mitigates Immune Cell Senescence and Boosts Vaccine Responses in Healthy Older Adults—A Pilot Study
    Aging Cell, 2026 · Randomized controlled trial · Supporting source
    This source discloses industry funding.
    Some of its authors disclose ties to industry.

Page history

Show all 6 changes to this page
  • — Rewritten to the content style guideline; ratings and sources unchanged.
  • — Source audit. The 2018 safety study of the wheat germ extract in mice and 30 older adults was removed, because the journal’s publisher reports that Web of Science has discontinued it from its Core Collection, a decision the publisher says it is appealing. The safety section drops that study's findings and now describes the evidence as two small trials; the 12-month trial authors' own account of the mouse kidney finding stays. No rating changed.
  • — Published. The claims, the longevity outcomes, the safety section and every source passed the site's source and wording reviews over four revision rounds. The owner's decisions on sources that could not be obtained are recorded in docs/08-open-decisions.md.
  • — Cited the Gostner and Fuchs letter on the Italian diet-and-mortality study, now read in full. The mortality summary describes the letter directly: it did not dispute the association, and argued from animal and laboratory evidence that extra spermidine intake is not without risk. No rating changed.
  • — Cited the study authors’ published reply to a letter on the Italian diet-and-mortality study. The mortality summary now reports, as the reply describes it, that the letter raised concern about polyamines and tumor development, and the reply’s statement that its finding on cancer deaths allows no conclusions on high-dose supplements. The mortality summary also reports, attributed to the reply, the authors’ view that studies show no convincing signal of tumor promotion at moderate doses, alongside their call for caution in people with cancer. The safety caution for people with cancer now also quotes the reply. The letter itself is still unread. No rating changed.
  • — Drafted. Memory in older adults, hair growth, helping people live longer, death from any cause, and blood markers of inflammation and immune-cell senescence all rated insufficient. No systematic review or meta-analysis of spermidine supplements was found; the hair rating rests on two EFSA opinions, and every other rating rests on single trials, animal work or observational studies of diet.