Best Spermidine Supplements 2026: 5 Products Compared

Last updated: September 26, 2026 · Originally published August 14, 2026 · Published by Eternal Elixir

Edited by Elaine Fletcher, Researcher

Disclosure: Eternal Elixir makes Spermidine 10mg, and it is our pick in this comparison. Every figure for the other four products comes from their own labels, supplement facts panels and product pages, checked in September 2026. No brand paid to be included. How we write and review content.

The best spermidine supplements in 2026 fall into two groups that look alike on a shelf. One group is capsules of spermidine trihydrochloride, a purified salt. The other is whole-food extracts made from wheat germ or other plants. The milligram figure on the front of the bottle means something different in each, so this guide converts every label to milligrams of actual spermidine, prices each product in USD, and sets the doses against what human trials have and have not shown.

Short answer: our pick is Eternal Elixir Spermidine 10mg. It puts 10 mg of spermidine trihydrochloride (about 5.7 mg of spermidine) in one capsule, holds 60 servings for $49.99, and names the salt form on the label. Double Wood has the lowest cost per milligram of spermidine, Omre puts the most spermidine in a daily serving (10 mg from wheat germ, with gluten), Codeage has the lowest bottle price, and Oxford Healthspan’s Primeadine is the whole-food option.

Quick Answer: The 5 Best Spermidine Supplements Ranked

1. Eternal Elixir Spermidine 10mg: our pick. One capsule a day, 10 mg of spermidine trihydrochloride, $0.83 a serving, 60 servings per bottle.
2. Double Wood Spermidine: lowest cost per milligram of spermidine at $0.117, two capsules per serving, with lot test results on the product page.
3. Omre Spermidine: most spermidine per serving, 10 mg from 1,000 mg of wheat germ, two capsules. Contains gluten.
4. Codeage Amen Spermidine: lowest bottle price at $24.99 for 30 capsules. Same salt dose per capsule as ours, plus 90 mg of vitamin C.
5. Oxford Healthspan Primeadine: whole-food spermidine at 1 mg per serving (Original, from wheat germ) or 1.2 mg (GF, from chlorella and citrus peel), $90.00 for a 30-day supply.

Four numbers worth knowing before you buy:

• 57%: the share of spermidine trihydrochloride’s weight that is spermidine. PubChem lists the molecule at 145.25 g/mol and the salt at 254.6 g/mol, so 10 mg of the salt carries about 5.7 mg of spermidine.
• 15 mg a day for 5 days: the dose that raised plasma spermine, but not plasma spermidine, in a 12-person crossover trial (Senekowitsch 2023).
• 0.9 mg a day for 12 months: the wheat germ dose in the largest and longest trial we found, in 100 older adults, which did not improve its primary memory measure (Schwarz 2022).
• $0.117 to $3.00: the spread in cost per milligram of spermidine across the five products below.

Best Spermidine Supplements 2026 Compared (Prices as of Sep 2026)

Each row is one daily serving as the label defines it. The spermidine column applies the 57% conversion to trihydrochloride products and uses the stated spermidine figure for whole-food products. Prices are one-time purchases of a single bottle on each brand’s own US store.

Two things stand out. The three trihydrochloride capsules deliver the same 5.7 mg of spermidine per serving, so the differences between them come down to capsule count, bottle size and price. The two wheat germ products sit at opposite ends: Omre concentrates its extract to reach 10 mg, while Primeadine Original gives 1 mg in a less processed form. Cost per milligram runs from $0.117 at Double Wood to $3.00 at Primeadine, a gap of more than 25 times.

How We Ranked These Spermidine Supplements

We did not run lab tests on any of these products. We read each current label, supplement facts panel and product page, converted every dose to milligrams of spermidine, and priced one bottle on each brand’s own store in September 2026. Five questions set the order:

1. How much spermidine does one daily serving deliver, and does the label say which form it is? A salt weight and a wheat germ spermidine figure are different units.
2. How many capsules does a serving take? Pill count is a common reason people drop a supplement after a few weeks.
3. What does it cost per serving and per milligram of spermidine? The sticker price hides bottle size.
4. What testing does the brand show on the product page? A lot number, a named lab and a measured result tell you more than a badge.
5. Who can take it? Wheat germ extracts carry gluten.

Eternal Elixir makes the product in first place. We rank it first because it gives the full salt dose in one capsule, names the form on the label, and costs the same or less per serving than three of the other four. It does not win every column. Double Wood is cheaper per milligram, Omre delivers more spermidine per serving, and both Double Wood and Omre publish lot-level test results on their product pages, which our product page does not. Each entry below says where a product beats ours.

Label Math: Spermidine Trihydrochloride vs Wheat Germ Spermidine

Most concentrated spermidine capsules hold spermidine trihydrochloride, often written 3HCl: the spermidine molecule bound to three hydrochloride groups so it stays stable and dissolves in water. The salt weighs more than the spermidine inside it. PubChem gives spermidine a molecular weight of 145.25 g/mol and the trihydrochloride 254.6 g/mol, so spermidine is about 57% of the salt by weight.

• 10 mg of spermidine 3HCl carries about 5.7 mg of spermidine. That covers one Eternal Elixir capsule, one Codeage capsule and a two-capsule serving of Double Wood.
• 5 mg of spermidine 3HCl, which is one Double Wood capsule, carries about 2.85 mg.
• Wheat germ products state the spermidine itself. Omre lists 1,000 mg of wheat germ standardized to 1% spermidine, which is 10 mg. Primeadine Original lists 1 mg per three capsules.

A “10 mg” salt capsule and a “10 mg” wheat germ serving are therefore different doses. Omre’s 10 mg is spermidine. Ours is 10 mg of the salt, which is 5.7 mg of spermidine. We spell that out here because the front of our own bottle says 10mg, and you should know what the number means before you compare it.

The same gap between the form on the label and the amount delivered shows up with other longevity supplements. Our guide to which glutathione supplements deliver a usable dose works through it for glutathione, and our Reduced L-Glutathione names the reduced form in its product name for that reason.

1. Eternal Elixir Spermidine 10mg: Our Pick for One Capsule a Day

Key specs: 10 mg spermidine trihydrochloride per capsule (about 5.7 mg of spermidine), 60 capsules, 1 capsule per serving, 60 servings, $49.99, which is $0.83 a serving. Ingredients: spermidine, rice flour, cellulose capsule.

This is our product. It sits first because it delivers the full 10 mg salt dose in a single capsule, with nothing else in the formula but rice flour and the capsule shell. Double Wood needs two capsules for the same 10 mg. Omre’s serving is two capsules and Primeadine Original’s is three. If you already take several capsules each morning, one fewer matters more than it sounds.

Codeage matches our dose in one capsule, so the comparison there is about the bottle. Codeage adds 90 mg of vitamin C and sells 30 capsules, which means a reorder every month. Ours holds 60 servings, and the multi-bottle pricing below takes the per-serving cost under Codeage’s.

The product page is plain about the evidence. It states that a long randomized cognition trial did not show a significant benefit on its primary outcome, and that autophagy “is not a guaranteed user outcome.” We would rather you buy with that in view than find it out later.

Where it costs more or does less: Double Wood is about 20% cheaper per milligram of spermidine, at $0.117 against our $0.146. Omre gives more spermidine per serving, 10 mg against our 5.7 mg. And our product page does not publish a lot-level certificate of analysis, while Double Wood’s and Omre’s do.

Buying more than one bottle: the product page takes 10% off two bottles, 15% off three and 20% off five. At the five-bottle tier each bottle works out to $39.99, or about $0.67 a serving, the same per-serving cost as a single bottle of Double Wood. Orders over $100 ship free in the US.

Pros:

• 10 mg of spermidine trihydrochloride in one capsule
• Salt form named on the label, so the dose converts exactly
• Single active ingredient with rice flour and a cellulose capsule
• 60 servings per bottle, with 10% to 20% off multi-bottle orders
• Product page states the null trial result instead of hiding it

Cons:

• Costs more per milligram of spermidine than Double Wood
• About 5.7 mg of spermidine per serving, less than Omre’s 10 mg
• No lot-level test results published on the product page

Suits: people who want a one-capsule spermidine dose with a clear label, especially if they already take other longevity capsules. Doesn’t suit: buyers chasing the lowest cost per milligram (Double Wood) or wanting a food-derived source (Omre or Primeadine).

For what spermidine is studied for and what each endpoint has shown, see our breakdown of spermidine benefits and dosage.

Add Spermidine 10mg to cart · $49.99

2. Double Wood Spermidine: Lowest Cost per Milligram of Spermidine

Key specs: 5 mg spermidine trihydrochloride per capsule, serving size 2 capsules (10 mg of the salt, about 5.7 mg of spermidine), 60 servings, $39.95, which is $0.67 a serving. Other ingredients: HPMC capsule, rice flour.

Double Wood is the value pick. At $0.117 per milligram of spermidine it is the cheapest product here on that measure, and the brand ships free in the US on orders over $30. The double pack costs $75.91 and the triple pack $107.87.

Its product page also shows the most testing detail of the five. The current lot (AILAB, manufactured 03/2026, tested by Canyonside Labs) measured 10.2 mg of spermidine trihydrochloride per serving against a claim of not less than 10 mg, with heavy metal and microbial results in the same table and the certificate of analysis linked as a PDF. We would like to see that document on every product in this category, ours included.

The label starts you at one serving a day and allows two servings after a week. The product page caps intake at 4 capsules, or 20 mg of the salt, a day. The trade-off is pill count, since the standard serving is two capsules.

Pros:

• Lowest cost per milligram of spermidine in this comparison
• Lot number, lab name and measured potency shown on the page
• 5 mg capsules let you adjust the dose in small steps
• Free US shipping from $30

Cons:

• Two capsules per standard serving
• No food-derived version

Suits: buyers who want the most spermidine per dollar and like to see lab numbers. Doesn’t suit: anyone trying to cut their daily capsule count. The page shows about 4.6 out of 5 from 27 reviews. Our Double Wood Supplements review covers the rest of the brand’s range and pricing.

3. Omre Spermidine: Most Spermidine per Serving

Key specs: 2 capsules provide 1,000 mg of wheat germ standardized to 1% naturally occurring spermidine, which the label gives as 10 mg of spermidine. 30 servings, $54.00 one-time ($1.80 a serving, $0.180 per milligram of spermidine), or $51.30 on a monthly subscription. Other ingredients: rice flour. Contains wheat and gluten.

Omre’s case is dose. Its 10 mg is spermidine itself, not a salt weight, so a serving carries about 75% more spermidine than a 10 mg trihydrochloride capsule. For a whole-food product that is a high figure, roughly ten times Primeadine Original’s 1 mg.

Omre also publishes a lab report. The lab report section on its product page names Certified Laboratories in Burbank, California, gives a batch test date of January 7, 2026, and reports 4.940 mg of spermidine per capsule by GC-FID analysis, which puts a two-capsule serving at about 9.9 mg. The report also screens for heavy metals and microbes.

The costs are price and gluten. At $1.80 a serving it runs a little over twice our per-serving cost for about 75% more spermidine. And because the spermidine comes from wheat germ, Omre states that the product contains wheat and gluten and is not suitable for people with celiac disease or a wheat or gluten allergy. The label says to take 2 capsules daily with any meal. US orders over $80 ship free.

What reviewers say: the product page showed 4.7 out of 5 from 119 reviews when we checked in September 2026. We can’t verify individual reviews and don’t summarize them as if we had. If you want to see how Omre handles its other longevity products, our Omre NMN review goes through that one in detail.

Pros:

• Highest spermidine per serving here, 10 mg
• Lab report with the lab named, a test date and a measured figure
• Food-derived spermidine for buyers who prefer it over a salt

Cons:

• $1.80 a serving, more than twice ours
• Contains wheat and gluten
• Two capsules per serving and 30 servings per bottle

Suits: buyers who want the highest spermidine figure in a food-derived form and have no gluten restriction. Doesn’t suit: anyone avoiding gluten or watching cost per serving.

4. Codeage Amen Spermidine: Lowest Bottle Price

Key specs: 1 capsule provides 10 mg of spermidine trihydrochloride (about 5.7 mg of spermidine) and 90 mg of vitamin C. 30 capsules, 30 servings, $24.99, which is $0.83 a serving and $0.146 per milligram of spermidine. Other ingredients: methylcellulose capsule, microcrystalline cellulose. Codeage describes it as vegan and gluten-free.

Codeage has the lowest sticker price here, and its dose and per-serving cost match ours exactly. The lower price comes from a smaller bottle: 30 capsules instead of 60. That makes it the cheapest way to try spermidine for a month before committing to more.

The formula adds 90 mg of vitamin C, 100% of the Daily Value on the label. That’s harmless for most people, but if you already take a multivitamin or a vitamin C supplement you’ll be doubling up, and if you want to judge spermidine on its own a single-active capsule is cleaner.

We rank it below ours for two reasons: you reorder twice as often, and our five-bottle price brings the per-serving cost to about $0.67, under Codeage’s $0.83. On a one-bottle basis the two are level.

Pros:

• Lowest bottle price, $24.99
• One capsule per serving, same salt dose as ours
• Labeled vegan and gluten-free

Cons:

• 30 servings per bottle
• Added vitamin C, which some buyers won’t want
• Same cost per milligram as ours on one bottle, higher than Double Wood

Suits: first-time buyers who want to test spermidine for a month at the lowest outlay. Doesn’t suit: people who want a single-active formula or a two-month bottle.

5. Oxford Healthspan Primeadine: The Whole-Food Option

Key specs (Original): 1 mg of whole-food spermidine per 3-capsule serving, from concentrated, defatted wheat germ extract sourced in Japan. 30-day supply, $90.00, which is $3.00 a serving and $3.00 per milligram of spermidine. Contains wheat, about 40 mg of gluten per serving. Other ingredients: corn-derived cluster dextrin, hypromellose capsule, sodium citrate.

Key specs (GF): 2 tablets a day providing 1.2 mg of naturally occurring spermidine from Okinawan chlorella, shikuwasa citrus peel and turmeric, plus lutein and nobiletin. 30-day supply, $90.00, which is $2.50 per milligram of spermidine.

Primeadine is the most expensive product here per milligram by a wide margin, and ranked on cost it would finish last. It is on the list because it is a different purchase. It delivers spermidine inside a food matrix with the other polyamines found in wheat germ, and the brand sells that as the point rather than the dose.

Its low dose also lines up with the human research more closely than the salt capsules do. The two Berlin memory trials used wheat germ extract at 1.2 mg and 0.9 mg a day, so Primeadine Original’s 1 mg sits between them. That does not mean it will reproduce any result, since only the smaller trial found one, but it is the closest match on this list to what those studies gave people.

The product page links two certificates of analysis, one for toxins and one for dose, and names Delta Labs of South Florida for its US testing, with further testing in Japan. It suggests building up from 1 capsule on day one to the full 3 capsules from day three. The Original showed 4.9 out of 5 from 183 reviews and the GF 4.8 from 48 reviews when we checked. US shipping is free over $100 or on a subscription.

Pros:

• Food-derived spermidine with the other polyamines in wheat germ
• Dose close to the wheat germ trials
• Toxin and dose certificates linked on the page
• A gluten-free version (GF) from a different food base

Cons:

• $3.00 per milligram of spermidine for the Original
• Three capsules a day for 1 mg
• Original contains gluten

Suits: buyers committed to a food-derived source who aren’t optimizing on cost. Doesn’t suit: anyone comparing on dose or price.

What Human Trials on Spermidine Have and Have Not Shown

Spermidine has a large body of cell and animal research behind it and a small human one. The table lists the human studies that matter for a buying decision, with the evidence level for each. Where a study used a different form or dose from ours, the table says so.

Read together, these studies make a short list of what is known. Spermidine at doses from under 1 mg to 40 mg a day has been well tolerated in trials lasting up to a year. One small pilot found a memory effect, and the larger 12-month follow-up did not confirm it. A pharmacokinetic study found that oral spermidine seems to be converted to spermine before it reaches the bloodstream, and its authors wrote that it is “rather unlikely that spermidine supplements with doses <15 mg/d exert any short-term effects.” The lifespan data come from mice, and the human diet data show an association, not cause and effect.

What has not been shown matters as much. No human trial has shown that a spermidine supplement extends lifespan, and none has tested our product or any other product on this list by name. Autophagy-related markers have been measured in immune cells in one small pilot, not as a general outcome you can expect from a capsule.

How Our Dose Compares With the Trial Doses

Our capsule supplies about 5.7 mg of spermidine a day. Here is how that sits against the studies above:

• Above the memory trials: about six times the 0.9 mg in SmartAge and nearly five times the 1.2 mg in the Berlin pilot. Both used wheat germ extract, not our salt, so a higher dose of a different form is not a guarantee of a stronger effect.
• Close to the immune pilot: just under the 6 mg a day used in the 13-week Oxford study, which also used wheat germ extract.
• Below the pharmacokinetic study: under half of the 15 mg a day that did not raise plasma spermidine over five days.
• Well below the safety ceiling tested so far: the 40 mg a day of spermidine trihydrochloride given for up to 28 days.

The plain position: our serve is in the middle of the range people have been given in trials, above the doses in the two memory trials and below the pharmacokinetic and safety doses. Nobody can tell you from current data that 5.7 mg is the right amount, and we won’t either.

Which Foods Have the Most Spermidine?

Wheat germ and soybeans are the richest common sources. A 2019 review of polyamines in food (Muñoz-Esparza et al., Frontiers in Nutrition) lists spermidine at up to 2,437 nmol/g in wheat germ and 1,425 nmol/g in soybeans. At that top value, a gram of wheat germ holds about 0.35 mg of spermidine, so 10 g would supply roughly 3.5 mg. Mushrooms, peas, hazelnuts, pistachios, spinach, broccoli, cauliflower and green beans also contain useful amounts.

Most cheeses are lower than their reputation suggests. The same review puts spermidine in most cheeses at under 69 nmol/g, with one blue cheese measured at 262 nmol/g. Food values vary with origin, growing conditions and storage, so treat any figure as a range.

Diet is also where the most encouraging human data sit. In the Bruneck study, people in the top third of spermidine intake had lower all-cause mortality over 20 years than those in the bottom third. That is an association in people who ate more whole foods, and it does not show that a capsule has the same effect.

Spermidine vs Fisetin, and Spermidine vs NMN

Fisetin is a plant flavonoid studied as a senolytic, meaning a compound that clears senescent cells. In mice, fisetin given late in life extended median and maximum lifespan (Yousefzadeh et al., EBioMedicine, 2018). Human fisetin trials published so far are small and measure short-term markers such as inflammation. Spermidine is studied mainly for its link to autophagy, the cell’s recycling process. The two act on different processes, and neither has a large human trial showing an aging outcome. We don’t sell fisetin.

NMN is a precursor to NAD+, a molecule involved in cellular energy metabolism, so it sits in a different part of a longevity routine. People who take both usually treat spermidine as the second addition. Our comparison of the best NMN supplements and our guide to NAD+ supplements cover that category, and NMN vs resveratrol explains how those two differ.

Spermidine Side Effects and Safety

The trials above reported spermidine as well tolerated. In SmartAge, adverse events were balanced between the spermidine and placebo groups over 12 months. The 3-month Berlin safety trial found no differences in vital signs, weight or blood tests. The 40 mg a day study reported no product-related adverse events over 28 days.

A few practical points apply:

• Wheat germ products (Omre and Primeadine Original) contain gluten and are not suitable if you have celiac disease, a wheat allergy or gluten intolerance.
• No drug interaction studies have been published for spermidine supplements. That reflects missing research, not proof of safety, so talk to your doctor before starting if you take any prescription medication.
• Do not use spermidine supplements if you are pregnant or breastfeeding, or give them to children, unless your doctor advises it. The trials enrolled adults only.

Which Spermidine Supplement Suits You

These five are not interchangeable, so match the product to the reason you’re buying:

• You want one capsule and a clear label: Eternal Elixir Spermidine 10mg, our pick. The full salt dose in one capsule, 60 servings, and the form named on the bottle.
• You want the most spermidine per dollar: Double Wood, at $0.117 per milligram, with lot results on the page.
• You want the highest spermidine figure from food: Omre, at 10 mg per two-capsule serving, if gluten is not a concern.
• You want to try spermidine for a month at the lowest outlay: Codeage, at $24.99 for 30 capsules.
• You want a whole-food matrix at a dose near the wheat germ trials: Primeadine Original, or Primeadine GF if you avoid gluten.
• You are not convinced by the evidence: that is a fair reading of the trials above. Spend on the parts of a routine you are more sure of first, and come back to spermidine if the next trials look better.

Where Spermidine Fits in a Longevity Routine

Most people who buy spermidine already take something else for healthy aging. The common pairing is an NAD+ precursor such as NMN, and some add calcium alpha-ketoglutarate. Each works on a different process, so they are usually combined rather than swapped.

If you are building a routine from scratch, start with our guide to the best longevity supplements and our breakdown of longevity supplement stacks. For calcium alpha-ketoglutarate, our review of what the Ca-AKG evidence supports and the Ca-AKG supplement comparison set out the human data. Our TUDCA supplement rankings and pterostilbene comparison cover two other single-active products in our range.

From our own range, NMN 500mg is 500 mg per capsule with 90 capsules and one capsule per serving, Ca-AKG 500mg is 60 capsules at one per serving, and TUDCA 500mg is 60 capsules at one per serving. You can compare them side by side below.

Frequently Asked Questions About Spermidine Supplements

Which brand of spermidine is best?

Our pick is Eternal Elixir Spermidine 10mg: 10 mg of spermidine trihydrochloride (about 5.7 mg of spermidine) in one capsule, 60 servings for $49.99, with the salt form named on the label. For the lowest cost per milligram, Double Wood is cheaper at about $0.117. For the most spermidine per serving, Omre gives 10 mg from wheat germ in two capsules but contains gluten. For the lowest bottle price, Codeage costs $24.99 for 30 capsules.

Add Spermidine 10mg to cart · $49.99

What are people saying about Omre spermidine in reviews?

Omre’s product page showed 4.7 out of 5 from 119 reviews when we checked in September 2026. We can’t verify individual reviews. What we can check is the label: 10 mg of spermidine from 1,000 mg of wheat germ per two-capsule serving, a lab report showing 4.940 mg per capsule, and a gluten warning. At $1.80 a serving it costs a little over twice as much as a one-capsule trihydrochloride product.

What food has the highest amount of spermidine?

Wheat germ, followed by soybeans. A 2019 review of polyamines in food lists spermidine at up to 2,437 nmol/g in wheat germ, about 0.35 mg per gram, and 1,425 nmol/g in soybeans. Mushrooms, peas, hazelnuts, pistachios, spinach, broccoli and green beans also contribute. Most cheeses are lower than often claimed.

What is better, fisetin or spermidine?

Neither has a large human trial showing an aging outcome, so neither is clearly better. They target different processes: fisetin is studied as a senolytic that clears senescent cells, with lifespan data from mice, and spermidine is studied for its link to autophagy. If you choose one, choose it for the process you care about and keep your expectations to what the human data show.

How much spermidine should I take per day?

Human trials have used from 0.9 mg to 40 mg a day. The memory trials used 0.9 mg and 1.2 mg from wheat germ, an immune pilot used 6 mg, and a pharmacokinetic study used 15 mg. One 10 mg trihydrochloride capsule gives about 5.7 mg of spermidine, which sits in the middle of that range. No dose has been shown to produce a health outcome, so follow the label and talk to your doctor if you take prescription medication.

Do spermidine supplements raise spermidine levels in the blood?

Not in the one study that measured it directly. Twelve healthy adults took 15 mg a day for five days, and plasma spermine rose while plasma and salivary spermidine did not. A 28-day study at 40 mg a day found little change in blood or urine polyamines. The authors of the first study think oral spermidine is converted to spermine before it enters the bloodstream.

Is spermidine from wheat germ better than spermidine trihydrochloride?

Neither is better in general. Trihydrochloride gives a precise dose, costs less per milligram and contains no wheat. Wheat germ extract delivers spermidine with the other polyamines in the food, which some buyers prefer, and the published memory trials used it, but it costs more per milligram and carries gluten. Choose trihydrochloride for a controlled dose and wheat germ if you want a food source.

What are the side effects of spermidine?

Trials from 0.9 mg to 40 mg a day reported spermidine as well tolerated, with adverse events similar to placebo. Wheat germ products contain gluten and are not suitable for people with celiac disease or a wheat allergy. No interaction studies exist, so talk to your doctor first if you take prescription medication, and do not use it while pregnant or breastfeeding unless your doctor advises it.

How much spermidine does David Sinclair take?

We can’t verify any individual’s supplement routine from a primary source, so we won’t repeat a figure. What you can check is the trial range above, from 0.9 mg to 40 mg a day. Base your dose on the label and those studies rather than on what a public figure is reported to take.

Which is better, NMN or spermidine?

They are not substitutes. NMN is a precursor to NAD+, which cells use in energy metabolism, and spermidine is studied for its link to autophagy. People who take both usually start with NMN and add spermidine second. Our NMN supplement comparison ranks eight US products if you’re choosing there first.

How long should you take spermidine before judging it?

The human trials ran from 5 days to 12 months, and the memory trials lasted 3 and 12 months. None identified a point at which people should expect to notice a change. If you try it, give it at least a few months and judge it against a clear reason for taking it, not a feeling.

Verdict: Which Spermidine Supplement Should You Buy?

Our pick is Eternal Elixir Spermidine 10mg. It delivers the full 10 mg salt dose, about 5.7 mg of spermidine, in one capsule, lasts 60 days, and says on the label and product page what the evidence does and does not show. Double Wood is the choice if cost per milligram matters most, Omre if you want the highest spermidine figure from food, Codeage if you want the lowest price for a first month, and Primeadine if you want a whole-food matrix and don’t mind paying for it.

Spermidine is an early-evidence supplement. It is well tolerated, and one large trial has found no memory benefit at a low dose. Buy it as an addition to a routine you already trust, keep the spend in proportion, and don’t let any roundup, this one included, talk you past that null result.

More Longevity Buying Guides

• Best NMN supplements compared
• Best NAD+ supplements
• Best TUDCA supplements
• Spermidine benefits and dosage
• All supplement guides
• The Eternal Elixir blog
• Shop the Eternal Elixir range or return to the Eternal Elixir home page

Sources

1. Senekowitsch S, et al. High-Dose Spermidine Supplementation Does Not Increase Spermidine Levels in Blood Plasma and Saliva of Healthy Adults. Nutrients. 2023;15(8):1852. PubMed 37111071
2. Schwarz C, et al. Effects of Spermidine Supplementation on Cognition and Biomarkers in Older Adults With Subjective Cognitive Decline: A Randomized Clinical Trial. JAMA Netw Open. 2022;5(5):e2213875. PubMed 35616942
3. Wirth M, et al. The effect of spermidine on memory performance in older adults at risk for dementia: A randomized controlled trial. Cortex. 2018;109:181-188. PubMed 30388439
4. Schwarz C, et al. Safety and tolerability of spermidine supplementation in mice and older adults with subjective cognitive decline. Aging (Albany NY). 2018;10(1):19-33. PubMed 29315079
5. Keohane P, et al. Supplementation of spermidine at 40 mg/day has minimal effects on circulating polyamines. Nutr Res. 2024;132:1-14. PubMed 39405978
6. Alsaleh G, et al. Spermidine Mitigates Immune Cell Senescence and Boosts Vaccine Responses in Healthy Older Adults: A Pilot Study. Aging Cell. 2026;25(6):e70545. PubMed 42169618
7. Kiechl S, et al. Higher spermidine intake is linked to lower mortality: a prospective population-based study. Am J Clin Nutr. 2018. PubMed 29955838
8. Eisenberg T, et al. Cardioprotection and lifespan extension by the natural polyamine spermidine. Nat Med. 2016. PubMed 27841876
9. Muñoz-Esparza NC, et al. Polyamines in Food. Front Nutr. 2019. PubMed 31355206
10. Yousefzadeh MJ, et al. Fisetin is a senotherapeutic that extends health and lifespan. EBioMedicine. 2018. PubMed 30279143
11. PubChem: Spermidine (CID 1102) and Spermidine trihydrochloride (CID 9539)
12. Product pages, checked September 2026: Eternal Elixir Spermidine 10mg, Double Wood Spermidine, Omre Spermidine, Omre certificate page, Codeage Amen Spermidine, Primeadine Original, Primeadine GF

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.