Spermidine

About Spermidine

A polyamine present in all living cells and in foods such as wheat germ, aged cheese, soybeans and mushrooms. Supplements are usually a wheat germ extract standardised for spermidine content rather than the isolated compound.

Spermidine has a strong mechanistic story — it induces autophagy, the cellular recycling process, and extends lifespan in yeast, flies, worms and mice — and a human record that has begun to arrive and has been sobering. The best-designed human trial to date randomised older adults with subjective cognitive decline to a spermidine-rich wheat germ extract for a year and found no significant benefit on memory, after a smaller three-month pilot had suggested there might be. Observational data linking higher dietary polyamine intake with lower mortality remain interesting and remain observational. There is also a specific unresolved question: polyamines support cell proliferation, and pharmacological polyamine depletion has been investigated as a cancer strategy, so supplementing them is not obviously benign.

Sold as

Wheat germ extract capsule, Powder, Combination longevity formulas

Standardised to

Milligrams of spermidine within a wheat germ extract; isolated synthetic spermidine is uncommon in retail products — a product without this marker may not resemble what was studied.

Also known as

Wheat germ extract spermidine, Polyamine supplement, Spermidine-rich extract

Regulation: Spermidine-rich wheat germ extract has been assessed and authorised as a novel food in the European Union, with conditions on the population and maximum intake. In the US it is a dietary supplement with no pre-market efficacy review.

What the research used

The amounts, forms and durations published trials of Spermidine actually administered.

When it was taken

Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.

In the food catalogue

The whole-food form, where one exists. The evidence for a concentrated extract rarely transfers to the food, or the other way round — these are cross-links, not equivalents.