Spermidine and longevity

Spermidine is a tiny molecule called a polyamine. Your body makes it. Your gut bacteria make some of it. And you eat it too. The awkward name comes from semen. In 1678, Antonie van Leeuwenhoek saw crystals in human semen that were later named spermine, spermidine's close chemical cousin ^[9]. The biology is what matters here, not the etymology.

So why do researchers care? One word: autophagy (your cells' built-in recycling program for damaged proteins and worn-out parts). Want the full mechanism story? See our autophagy guide. Here is the short version. Autophagy slows down as you age. Junk proteins pile up. Cells work less well. And almost everything that extends life in animals, from eating less to rapamycin to exercise, flips autophagy back on. Spermidine does the same thing.

The paper that started it all landed in 2009. A Graz-led team showed in Nature Cell Biology that spermidine made yeast, worms and flies live longer. The catch: it only worked when the autophagy genes were intact ^[1]. Seven years on, the same group went bigger. In Nature Medicine they put spermidine in mouse drinking water, and the mice lived longer and had healthier hearts in old age. Switch off autophagy, and the benefit vanished ^[2]. The same 2016 paper also looked at 829 people from the Bruneck cohort in South Tyrol. Those who ate more spermidine had lower blood pressure and less heart and blood-vessel disease. The link held for high blood pressure, coronary artery disease (narrowed heart arteries), stroke and vascular death ^[2].

The link to dying from any cause showed up two years later. A 2018 analysis added longer follow-up and checked the signal again in a second cohort near Salzburg ^[4]. Then a 2024 paper from the Graz group, again in Nature Cell Biology, found something neat. Fasting pushes up spermidine levels in yeast, flies and mice, and in the blood of human volunteers ^[10]. Block the polyamine pathway, and fasting stops extending lifespan in yeast, worms and flies. So spermidine looks like one of the molecules that delivers the payoff of eating less.

One honest caveat before you get excited. Nearly all of this is animal and cell biology. The mouse results are solid. But whether they carry over cleanly to people is a separate question, and the human data gets messier, as you will see below.

Spermidine is one of the few longevity compounds whose research heartland sits in the German-speaking world. Most of the groundwork comes from the Frank Madeo lab at the University of Graz in Austria, with the key human signal from the Italian-South-Tyrolean Bruneck cohort. That concentration is a quirk most people miss. It matters because it shapes how much independent replication exists. The Graz work (the university's full name is Karl-Franzens-Universität) runs through BioTechMed-Graz. These all trace back to this Graz axis:

• the 2009 yeast paper
• the 2016 Nature Medicine mouse study
• the 2018 Science review ^[3]
• the SmartAge trial protocol with Charité Berlin
• the 2024 Nature Cell Biology fasting paper

Two things follow from that. First, the Bruneck cohort that tied dietary spermidine to lower mortality is Italian-South-Tyrolean, a German-speaking corner of northern Italy. Second, the only spermidine ingredient with EU Novel Food approval, a wheat germ extract, comes from Longevity Labs+, a spin-off based in Graz, Austria. They sell it under the brand spermidineLIFE.

None of this means the science is settled. None of it means the Austrian product is automatically your best buy. It just means that when you open a recent peer-reviewed spermidine paper, the odds are good that Frank Madeo is on the author list. Knowing where research comes from helps you read it honestly. The Madeo group discloses its ties openly, and they are worth knowing. Several lead authors, Madeo, Eisenberg and Sigrist among them, hold shares in Longevity Labs+ (legally TLL The Longevity Labs), the Graz company behind the approved extract ^{[6, 8]}. The company supplied the capsules for the Berlin safety trial ^[6], and its then CEO co-authored SmartAge ^[8]. That is common in nutrition science and not a scandal. But it is context worth carrying with you. The Wiener Neustadt nursing-home trial, by contrast, was paid for by its own authors ^[7].

Two other DACH centers have run human spermidine trials: FH Wiener Neustadt, a university of applied sciences south of Vienna (Pekar group), and Charité Berlin with DZNE partners (Wirth, Schwarz, Flöel). Together with Graz, those three labs ran almost every human trial up to 2022. Newer trials come from Germany, the UK and Denmark, plus one run by a maker of synthetic spermidine ^{[14, 15, 16, 17]}.

Human evidence points in two directions. Studies that watch what people eat link more spermidine to fewer deaths. In the Bruneck Study, each 1-SD step up in intake came with about 26 percent lower risk of dying from any cause. One SD, or standard deviation, is a typical gap between people. The hazard ratio was 0.74 (95% CI 0.66 to 0.83, the range the true value most likely sits in). The top third of eaters versus the bottom third had a death rate like being about 5.7 years younger ^[4]. But the best randomized trial, SmartAge, was NEGATIVE: 12 months of supplements did nothing for memory ^[8]. So the diet signal is encouraging while the one strong RCT is not. Let me walk you through both.

What we learn from watching people eat.

The Bruneck Study tracked 829 adults aged 45 to 84 in northern Italy from 1995 to 2015 ^[4]. Researchers used food questionnaires to estimate how much spermidine each person ate. The people eating the most had a much lower risk of dying from any cause. The standout numbers:

• Raw death rates by third of intake: 40.5, then 23.7, then 15.1 deaths per 1000 person-years (think 1000 people followed for one year).
• Top third vs. bottom third: a gap the authors put at about 5.7 years of age (95% CI 3.6 to 8.1). The top eaters died at the rate of people about 5.7 years younger.
• Per 1-SD more spermidine: HR 0.74 (95% CI 0.66 to 0.83), adjusted for age, sex and energy intake. That is about 26 percent lower risk.
• Fully adjusted for age, smoking, BMI, calorie intake, physical activity and more: HR 0.76 (95% CI 0.67 to 0.86). The signal held.
• Second cohort: the same pattern showed up on its own in the Salzburg-area SAPHIR cohort: HR 0.71 per 1-SD.

That is a real signal, and an impressive one. But it is still just observation. People who eat lots of spermidine also eat lots of whole grains, legumes and aged cheese. They eat Mediterranean-style. So was it the spermidine doing the work, or was spermidine just a tag-along marker for a healthy diet? Watching people eat cannot answer that.

What we learn from controlled trials.

The biggest randomized trial so far is SmartAge, published in JAMA Network Open in 2022 ^[8]. A hundred older adults with subjective cognitive decline (they felt their memory slipping, but standard tests still looked normal) took spermidine-rich wheat germ extract (about 0.9 mg spermidine per day) or a placebo for 12 months. The main thing they measured was memory, using a Mnemonic Similarity Task (telling pictures you saw before apart from very similar new ones). The result: SmartAge was NEGATIVE on its main goal. No measurable boost to memory. None to blood biomarkers. None on brain MRI. And none on most of the secondary measures either.

An earlier, smaller pilot in Cortex had looked mildly promising: 30 people over three months, with a medium-sized effect on memory discrimination, the ability to keep similar memories apart ^[5]. The bigger, longer SmartAge trial could not repeat it. That is exactly how science is supposed to run. Small positive pilot, then a larger trial to see if it holds. Here, it did not.

Two newer trials add a twist and a glimmer. In a 2023 German absorption study, even 15 mg a day for five days did not raise spermidine in the blood. Spermine, which the body builds from it, went up instead ^[14]. And a 2026 Oxford pilot in 40 adults over 65 found that 6 mg a day for 13 weeks was well tolerated. It also improved COVID vaccine antibody responses, but only in people whose earlier doses had barely worked ^[16]. That is small and early, but it is the first randomized hint of an immune effect.

The signal pointing the other way.

A 2020 paper in Wiener Klinische Wochenschrift ran a three-month double-blind pilot (neither residents nor testers knew who got which dose) across six nursing homes in Styria, Austria, with 85 older people aged 60 to 96. Most had some degree of dementia, but 23 had none. Everyone ate breakfast rolls six days a week. One group got wheat germ rolls (3.3 mg spermidine each), the other wheat bran rolls (1.9 mg each). In the 18 people with mild dementia in the wheat germ group, MMSE scores (a common dementia screening test) rose 2.23 points from baseline (p = 0.026) ^[7]. That is a before-and-after change inside one small subgroup, not a head-to-head win over the other group. The caveats are big, though. There was no true placebo arm, since both groups got spermidine, just at different doses. The sample was small. On the plus side, the authors paid for it themselves, with no industry money ^[7]. And most of these people already had dementia, unlike the worried-but-healthy folks in SmartAge. So it does not cancel out SmartAge. It is just one reason the door on cognitive benefit is not fully shut.

The same team then followed 45 nursing-home residents who got 3.3 mg of spermidine a day with their food for a full year. MMSE scores rose by 5 points on average ^[18]. There was no control group, so normal ups and downs or simply getting used to the test cannot be ruled out.

The honest read. For cognition in healthy older adults at risk for dementia, the best trial we have says no benefit. For all-cause mortality, two observational cohorts point the same way; the heart-specific signal comes from one cohort ^{[2, 4]}. The mechanism (autophagy) is plausible. None of that tells you to take spermidine or to avoid it. It is simply where the evidence stands in 2026.

The richest common food source of spermidine is wheat germ, at roughly 24 to 35 mg per 100 g, followed by soybeans, mushrooms, green peas and white beans. A normal mixed European diet delivers about 5 to 15 mg per day, so people were eating it long before anyone pressed it into a pill. The most thorough peer-reviewed food database we have is a 2019 polyamine survey in Frontiers in Nutrition ^[9]. The numbers below are rounded from that paper and other food databases, which often disagree. Heads up: they swing a lot with variety, ripeness, processing and storage. Treat them as ballpark figures, not lab-precise readings.

Food	Approximate spermidine	Notes
Wheat germ (raw or toasted)	~24 to 35 mg/100 g	The single richest common food source
Soybeans (dried)	~15 to 20 mg/100 g	Plus tofu, natto, tempeh
Aged cheese (cheddar, parmesan, blue)	~1 to 4 mg/100 g	Highest in blue cheese; some databases list aged cheddar far higher
Mushrooms	~3 to 6 mg/100 g	Higher in shiitake and oyster
Green peas	~5 to 7 mg/100 g	Fresh; canned slightly lower
Navy beans, white beans	~5 to 12 mg/100 g	Cooked from dry
Broccoli, cauliflower	~2 to 3 mg/100 g
Pears, apples	~0.1 to 0.3 mg/100 g
Whole grain bread	~0.5 to 1 mg/100 g

A sensible mixed European diet gives you somewhere between 5 and 15 mg of spermidine per day. The top third of the Bruneck cohort landed around 12 mg/day. Eat Mediterranean-style, with whole grains, legumes, vegetables and a bit of aged cheese, and you hit that range without even trying.

Want the densest real food? It is wheat germ, hands down. One tablespoon (about 7 g) of toasted wheat germ gives you roughly 2 mg of spermidine, the same ballpark as a typical supplement capsule. It costs a few euros per kilogram at any DACH supermarket. Stir it into yogurt, muesli, smoothies or bread.

One more wrinkle. Your gut bacteria make spermidine too. A decent chunk of the spermidine in your body never came from food at all. That is part of why the dose-response picture from supplements alone stays fuzzy: you are stacking a capsule on top of a personal baseline that swings a lot from person to person.

The only spermidine supplement approved in the EU is spermidine-rich wheat germ extract from Triticum aestivum. EU Novel Food rules cap it at the equivalent of 6 mg spermidine per day for adults ^[12]. There is no approved EU health claim, and synthetic spermidine is not authorized. Anything else is either a compliant wheat germ product or a legal gray zone. This section is vendor-neutral on purpose. You are an adult, you can shop where you like. Our job is just to lay out the legal status and the evidence so you can decide.

The EU Novel Food rule. In the EU, any food ingredient that nobody ate in real amounts before 1997 counts as a Novel Food under Regulation (EU) 2015/2283, and it needs explicit approval before it can be sold. One spermidine ingredient has that approval: spermidine-rich wheat germ extract from Triticum aestivum, originally developed by Longevity Labs+ (Graz, Austria). The maker notified the EU in December 2017 through a shortcut route under the old Novel Food law, a so-called substantial-equivalence notification. That route involved no full safety review by EFSA (the EU food-safety agency). The extract now sits on the EU's Union list of novel foods (Implementing Regulation (EU) 2017/2470) ^[12]. On 25 March 2020, Commission Implementing Regulation (EU) 2020/443 changed its specifications: it raised the allowed level of cadaverine, an amine that occurs naturally in wheat germ ^[13]. The Union list's conditions of use cap a food supplement for adults at the equivalent of 6 mg of spermidine per day, and it leaves out pregnant and breastfeeding women ^[12]. Supplement labels in Germany, Austria and Switzerland have to match those specs.

No approved health claim. Let me be blunt: there is no approved EU health claim for spermidine. The closest anyone got was a 2011 EFSA review of a proposed claim that spermidine keeps hair in its growth phase. EFSA ruled that the claim was really about treating a hair-loss condition (chronic telogen effluvium), which health claims on food are not allowed to cover. So the claim was NOT approved ^[11]. So any marketing hinting that spermidine prevents disease, extends your life or regrows hair is running ahead of what regulators have actually signed off.

What this means when you shop. A spermidine supplement sold legally in Germany, Austria or Switzerland does one of three things. It uses the approved Longevity Labs+ wheat germ extract. Or it uses a different wheat germ extract that still fits the Novel Food approval. Or it sits in a legal gray zone, sometimes sold across borders or labeled as a plain 'wheat germ' product that does not openly advertise its spermidine. Pure synthetic spermidine, by the way, is not approved as an EU food supplement.

Two labels deserve a closer look. 'Spermidine trihydrochloride' is a synthetic salt form of spermidine. One industry-funded trial tested it at 40 mg a day ^[15]. It is not an authorized EU food ingredient. And buckwheat sprout flour grown with added synthetic spermidine has no EU approval either, according to Germany's consumer advice centers (April 2026) ^[19].

Which doses are actually backed by trials? Here are the human trials so far, sorted by dose:

Study	Spermidine per day	Duration	Who	Result
SmartAge 2022 [8]	~0.9 mg (capsules)	12 months	100 older adults with memory worries	No memory benefit
Cortex pilot 2018 [5]	~1.2 mg (capsules)	3 months	30 older adults with memory worries	Small memory effect
Styria 2020 [7]	1.9 or 3.3 mg per roll, 6 days a week	3 months	85 nursing-home residents, most with dementia	MMSE gain in a small subgroup, no placebo
Styria follow-up [18]	3.3 mg with food	12 months	45 nursing-home residents	MMSE up 5 points, no control group
Vaccine pilot 2026 [16]	6 mg	13 weeks	40 adults over 65	Well tolerated, better antibodies in weak vaccine responders
Absorption study 2023 [14]	15 mg	5 days	12 healthy adults	Blood spermidine unchanged
POLYCAD [17]	24 mg	48 weeks	187 heart patients aged 65+	Results pending
Safety trial 2024 [15]	40 mg (synthetic)	28 days	37 men aged 50 to 70	No safety signal, blood polyamines barely moved

The Bruneck cohort thirds spanned roughly 6 to 12 mg/day, all from food. Most approved supplements give you somewhere in the 1 to 3 mg/day range per serving. That sits at the low end of the studied band and of the dietary cohort signal. Doses above 6 mg have so far been tested for absorption and safety, not for benefit. The 24 mg heart trial will be the first, and its results are still pending.

Now, the money. A month's supply of an EU-approved spermidine wheat germ supplement in DACH usually runs 30 to 70 euros. Prices wobble by country: Switzerland tends to be priciest, Austria often cheapest, since the maker is right there. A bag of plain wheat germ at the same supermarket costs about 3 to 5 euros and lasts a month at one tablespoon a day. The supplement gives you a measured, standardized dose. The wheat germ gives you that dose plus fiber, magnesium, vitamin E, B vitamins and zinc. Neither choice is wrong. They are just different products.

What we honestly cannot tell you. Whether brand A beats brand B. Whether a higher-dose unapproved import is safer or more effective than the EU-approved one (it is not generally safer, just less regulated). Whether timing matters. Whether spermidine works better paired with fasting (the 2024 fasting paper makes that plausible on paper ^[10], but no published human trial has tested it). These are open questions. Use this guide to ask sharper ones at your Hausarzt, Wahlarzt or Privatarzt appointment, especially if you have a chronic condition or take medication.

Short answer. Spermidine is already in everyone's normal diet. In trials, side effects have been rare. At the doses tested so far, the safety record looks reassuring. That covers about 1 mg a day in capsules for up to 12 months ^{[6, 8]} and up to 3.3 mg a day from wheat germ bread rolls ^[7]. It also covers 6 mg a day for 13 weeks ^[16] and even 40 mg a day of synthetic spermidine for 28 days ^[15]. The record is also short, which matters just as much.

A 2018 safety paper in Aging pooled animal and human data and found no clinically meaningful red flags for spermidine-rich wheat germ extract over three months in older adults ^[6]. The 12-month SmartAge trial also reported no serious side effects tied to the supplement ^[8]. And the EU Novel Food approval caps daily intake for adults and keeps certain groups out of the approved use.

Where to be careful.

• Pregnancy and breastfeeding. The EU Novel Food approval for spermidine-rich wheat germ extract leaves out pregnant and breastfeeding women. Not because harm turned up, but because nobody has established safety for that group. Pregnant or breastfeeding? Stick to food sources.
• Children. Same reasoning. The approval does not cover kids. Spermidine from food is fine. Concentrated capsules are not the right call.
• Active or recently treated cancer. This is the trickiest question in the whole field. Spermidine drives autophagy, and autophagy can either protect you or feed tumor growth, depending on the cancer type and stage. The 2018 safety paper points to mouse studies. There, a lifetime of spermidine in the diet did not make tumors more common. In some chemically triggered liver cancer models it even protected against them ^[6]. But the human evidence in active cancer patients is basically zero, and Madeo's own group cautions that polyamine-driven autophagy could, in principle, prop up tumors that already exist. Germany's consumer advice centers also warn that high doses may speed the growth of certain tumors ^[19]. If you have active or recently treated cancer, do not start a spermidine supplement without your oncologist's input.
• It comes from wheat germ. Spermidine supplements made from wheat germ contain gluten, even if only a trace. If you have celiac disease or non-celiac gluten sensitivity, pick a certified gluten-free product or skip the supplement.
• Drug interactions. No major direct drug interactions are on record at the studied supplement doses. That is not the same as saying none exist. If you take immunosuppressants, cancer drugs or strong autophagy modulators (rapamycin, high-dose metformin, hydroxychloroquine), have that conversation with your Hausarzt or Wahlarzt before adding spermidine.

What we still do not know.

• Whether taking it for decades is safe. The longest human trial ran 12 months.
• Whether it prevents dementia in people with no symptoms yet (SmartAge enrolled people with subjective cognitive decline, not unaffected adults).
• Whether the heart-related signal from cohorts holds up in a randomized trial. A Danish trial, POLYCAD, has randomized 187 heart patients aged 65+ to 24 mg a day or placebo for 48 weeks; results are not yet published ^[17].
• Whether spermidine plus fasting, exercise or rapamycin adds up to extra benefit in people (the 2024 fasting paper makes the fasting combo biologically plausible ^[10]).

For any health call based on this guide, talk to your Hausarzt (Germany), Wahlarzt or Privatarzt (Austria) or Hausarzt / Spezialist (Switzerland). This guide is education, not a prescription.