Best spermidine supplements to buy in 2026.
25 spermidine products from 19 brands are tracked here. The dose that matters is measured in milligrams, not hundreds of milligrams, and most labels hide it behind a wheat-germ extract weight. Evidence grade B rests on a positive 30-person pilot, a null 12-month follow-up trial in 100 people, and one ongoing cancer-supportive-care RCT with no results posted.
Top picks: 25 spermidine products from 19 brands, ranked.
Sorted by overall score. Trial dose for spermidine is 1.2 mg per day, with a published range of 0.9 mg to 6 mg. Cost per day at trial dose is what it costs to reproduce the published dose, not the sticker price of a bottle. What is RxD-$?
ProHealth Longevity Pure Spermidine - 1 mg, 180 capsules
AgeMate Daily Longevity Blend
Innerbody Labs NAD+ Support
Neurogan Health Spermidine Tablets
| # | Product | Composite | Dose | Cost at trial dose | 3rd-party tested | Public lab certificate |
|---|---|---|---|---|---|---|
| 1 | ProHealth Longevity Pure Spermidine - 1 mg, 180 capsules | 7.1 | 83% | $0.20/day | Yes | Yes |
| 2 | AgeMate Daily Longevity Blend | 7.0 | 167% | $1.38/day | Yes | No |
| 3 | Innerbody Labs NAD+ Support | 7.0 | 140% | $1.76/day | Yes | Yes |
| 4 | DoNotAge Pure Spermidine | 6.9 | 833% | $0.24/day | Yes | Yes |
| 5 | IM8 Daily Ultimate Essentials | 6.9 | 25% | $17.20/day | Yes | No |
Why these?
One formula, applied to all 307 products on the site. No brand pays to be here.
The overall score is a weighted sum of six pillars:
- 0.50 Dose and evidence. How close the label serving sits to the dose used in published human trials, weighted by how good that evidence is.
- 0.20 Transparency. Public batch-specific Certificate of Analysis, named lab, stated actives.
- 0.10 Value. Cost per day at trial dose, compared against the rest of the category.
- 0.10 Formulation. Form, bioavailability, and whether the delivery matches the trial material.
- 0.05 Safety. Documented adverse events, contamination history, interaction load.
- 0.05 Community. Verified consumer reports, weighted down hard because reviews are noisy.
Dose carries half the weight because a well-tested product at a quarter of the trial dose is still a product that cannot reproduce the trial. Read the full methodology for the arithmetic and the sensitivity analysis.
What the evidence shows.
Spermidine carries evidence grade B on this site. Every study below is linked to its source. Nothing here is summarised from a secondary write-up.
The effect of spermidine on memory performance in older adults at risk for dementia: a randomized controlled trial
The Phase IIa pilot that started the field. 30 adults aged 60 to 80 with subjective cognitive decline took a spermidine-rich wheat-germ extract or placebo for three months. Memory on the Mnemonic Similarity Task improved moderately in the spermidine arm: contrast mean 0.17, 95 percent CI −0.01 to 0.35, Cohen's d 0.77. The confidence interval crosses zero. 30 people and three months, which is why the same group ran a bigger trial to test it. Registered as NCT02755246.
Effects of spermidine supplementation on cognition and biomarkers in older adults with subjective cognitive decline (SmartAge)
The 12-month Phase IIb follow-up to that pilot, and it was null. 100 participants, 51 on spermidine and 49 on placebo, mean age 69, given 0.9 mg of spermidine per day from wheat-germ extract or a microcrystalline cellulose placebo. Primary outcome was mnemonic discrimination on the Mnemonic Similarity Task. Between-group difference −0.03, 95 percent CI −0.11 to 0.05, P = .47. No secondary outcome reached significance either. Exploratory analyses hinted at verbal memory and inflammation, and adverse events were balanced. 89 of 100 completed. Registered as NCT03094546.
A trial of spermidine for the prevention of radiation-induced xerostomia
A registration, not a result. 58 head and neck cancer patients are randomised to spermidine capsules twice daily with meals or placebo, starting one week before radiotherapy and continuing to one week after it. Primary outcome is the Xerostomia Questionnaire score, assessed weekly out to three months after treatment. The trial started in June 2025, is still recruiting, and has posted no results. Any dry-mouth percentages you see quoted for spermidine are not from this trial, because this trial has not reported.
How to choose.
- Buy on labelled spermidine milligrams, not extract weight. "Wheat germ extract 800 mg" can mean 0.8 mg or 8 mg of actual spermidine. That is a tenfold spread in what you are paying for. If the label does not state spermidine content in milligrams, you cannot compare it against anything and neither can we.
- Target 0.9 mg to 6 mg of spermidine per day. SmartAge, the largest and longest trial, used 0.9 mg per day from wheat-germ extract for 12 months. This is a milligram-scale molecule. A product advertising "1,000 mg spermidine" is advertising extract weight and hoping you do not notice.
- Wheat-germ extract or synthetic, both work if the content is verified. Source matters less than a dated third-party Certificate of Analysis that confirms the spermidine number. Wheat-germ products carry gluten exposure for coeliac buyers. Third-party testing definition.
- EU status depends on the concentration. Wheat-germ extract is treated as a traditional food in the EU. Concentrates above 7 mg fall under novel food rules. Standard wheat-germ spermidine at trial doses ships into the EU without the problem NMN has. See the regulatory tracker.
Common questions
How much spermidine per day do trials use?
SmartAge, the largest and longest trial, used 0.9 mg per day for 12 months. The published range across trials runs from 0.9 mg to about 6 mg. Doses are single-digit milligrams, not hundreds of milligrams.
Why do spermidine labels list 800 mg or more?
That number is the weight of the wheat-germ extract, not the spermidine in it. The same 800 mg of extract can contain 0.8 mg or 8 mg of spermidine. Only labelled spermidine content is comparable.
Does spermidine improve memory?
The best available trial says no. Schwarz C and colleagues gave 100 older adults with subjective cognitive decline 0.9 mg of spermidine per day or placebo for 12 months and found no effect on mnemonic discrimination: difference −0.03, 95 percent CI −0.11 to 0.05, P = .47. A 30-person three-month pilot in 2018 had suggested a benefit. The larger trial did not confirm it.
Can I get enough spermidine from food?
Wheat germ, aged cheese, mushrooms, and soy products all contain spermidine. Dietary intake in the milligram range is achievable, which is one reason the supplement case is weaker here than for molecules with no food source.
Is spermidine legal in the EU?
Wheat-germ extract is treated as a traditional food in the EU. Concentrates above 7 mg are handled under novel food rules.
Is spermidine safe to take long term?
The 12-month SmartAge trial reported adverse events balanced between spermidine and placebo, with 89 of 100 participants completing. Data past 12 months does not exist. Polyamine levels have been flagged in specific disease contexts, so ask a clinician if you have an active cancer diagnosis.
Go deeper
Questions or a correction on any number on this page: [email protected].