Spermidine is a polyamine — a small molecule your body makes naturally and absorbs from food — that is found in every human cell. Levels drop steadily as we age, and this decline is thought to contribute to many signs of getting older. Supplementing with spermidine, or eating foods naturally rich in it, is one of the most researched approaches to supporting the body's built-in cellular renewal systems.

Spermidine's most important job is switching on autophagy — the process your cells use to break down and recycle damaged or worn-out components. Think of it as your body's internal housekeeping crew. By keeping this process active, spermidine helps clear out cellular debris, supports healthy DNA, and keeps cells functioning more like younger versions of themselves. It also helps regulate inflammation and supports the health of mitochondria, the tiny energy generators inside every cell.

Most supplements use a standardized wheat germ extract delivering 1–3 mg of spermidine per serving. Capsules are the most convenient form. Powders can be mixed into food or drinks. Eating spermidine-rich foods daily is a valid alternative or complement to supplements.

• Aging and longevity support
• Memory and cognitive decline
• Heart health and cardiovascular risk
• Immune system support
• Hair thinning and hair growth
• Liver health
• Sleep quality
• Inflammation (chronic, low-grade)

• Cardiovascular mortality — higher dietary spermidine intake is associated with reduced risk of dying from heart disease in large cohort studies
• Age-related memory decline — clinical trial evidence supports a protective effect on memory in older adults at risk of cognitive deterioration

• Wheat germ — The single richest commonly available food source of spermidine, containing roughly 243 mg per kg — this is why most supplements use wheat germ extract as their base
• Mature (aged) cheeses — Aged cheeses like cheddar, gouda, and parmesan are among the richest animal-derived sources; fermentation during aging increases polyamine content significantly
• Soybeans and soy products (natto, miso, tempeh) — Fermented soy products are especially high; natto in particular combines spermidine with other longevity-linked compounds like vitamin K2
• Mushrooms — Many edible mushroom species, particularly shiitake and oyster mushrooms, are good plant-based sources of spermidine and easy to incorporate daily
• Green peas and legumes — Green peas, lentils, and chickpeas provide meaningful spermidine alongside fiber and other nutrients that support gut bacteria which also produce polyamines

• Mild nausea or stomach discomfort at higher doses
• Loose stools or diarrhea, particularly when starting supplementation
• Headache (uncommon, typically resolves within the first week)
• No known serious adverse effects at dietary or standard supplemental doses in healthy adults

• Recommended daily: 1–3 mg of spermidine per day from a standardized wheat germ extract supplement; typical dietary intake from food ranges from 7–25 mg/day total polyamines
• Best time of day: Morning or early afternoon is most commonly used in studies; no strong evidence for a specific timing advantage, but avoiding late evening may be prudent given potential effects on cellular energy
• With or without food: Take with food to reduce the chance of mild digestive discomfort; absorption is not significantly affected by food
• Time to effect: Cellular autophagy markers may shift within 4–8 weeks; cognitive and cardiovascular benefits in studies emerged over 3–12 months
• How long to take it: Intended for long-term daily use — longevity benefits are cumulative and linked to sustained intake. No cycling protocol is established or recommended. Regular use mirrors the consistent dietary intake seen in longevity-associated populations.