Spermidine is a natural polyamine in our cells, organs, and circulation. It is a popular supplement because it plays several vital roles in the body, including supporting cell growth and proliferation and inducing autophagy, a process of cellular recycling and renewal.
The human body's spermidine levels depend on internal production, either by cells or gut bacteria, and external sources from diet or supplementation.
If you are looking to maximize the effects of spermidine supplementation keep reading!
Absorption and bioavailability
After ingestion, spermidine reaches the gut and quickly crosses the intestinal barrier. Before entering the circulation, spermidine is metabolized into spermine, resulting in elevated blood spermine levels (rather than spermidine). However, short-term supplementation, such as five days, does not appear to increase levels of spermine (1).
If you want to continuously raise your levels of spermidine, take spermidine regularly. This was confirmed in a study where healthy male volunteers consumed a spermidine-rich diet eating natto (fermented soybeans) every day for two months. As a result, they had elevated blood spermine levels (2).
How to consume spermidine?
Following a diet rich in spermidine or using spermidine supplements can be an effective way to boost polyamine levels. Spermidine is abundant in certain plant-based foods, such as:
- soybeans,
- mushrooms,
- wheat germ,
- green pepper,
- broccoli, etc.
Spermidine is water-soluble, so it does not need to be taken with meals or fatty foods, unlike some other supplements. However, since spermidine naturally occurs in various foods, supplementation can be taken with regular meals. For individuals prone to gastrointestinal symptoms, it is a good idea to take spermidine with food.
Spermidine - Recommended Dosage
The average dietary intake of spermidine in Europe and the United States ranges from approximately 8 to 15 mg/day, primarily sourced from plant-based foods (3).
Clinical studies
A daily intake of 750 mg of a plant extract containing 1.2 mg of spermidine has shown positive effects on memory in older adults (4), while the same amount of plant extract with 0.9 mg of spermidine per day reported no significant benefits (5).
Additionally, positive effects on dementia were observed in a high-dose group consuming grain rolls with wheat germ containing 3.3 mg/day of spermidine six times per week, compared to a low-dose group receiving 1.9 mg/day (6). These findings suggest that higher doses may be more likely to produce positive results.
Spermidine - Safety Considerations
The European Union has authorized spermidine-rich wheat germ extract containing up to 6 mg/day of spermidine (7). Additionally, a study administering a very high dose of pure spermidine (40 mg/day) for one month in healthy older adults reported it to be safe and well-tolerated (8).
In summary, while higher doses of spermidine supplementation (~3 mg/day) have shown potential benefits and are generally considered safe, there is not enough evidence to establish specific dosage recommendations.
Read our other articles on spermidine:
Literature sources:
- Senekowitsch S, Wietkamp E, Grimm M, Schmelter F, Schick P, Kordowski A, Sina C, Otzen H, Weitschies W, Smollich M. High-Dose Spermidine Supplementation Does Not Increase Spermidine Levels in Blood Plasma and Saliva of Healthy Adults: A Randomized Placebo-Controlled Pharmacokinetic and Metabolomic Study. Nutrients. 2023 Apr 12;15(8):1852. doi: 10.3390/nu15081852.
- Soda K, Kano Y, Sakuragi M, Takao K, Lefor A, Konishi F. Long-term oral polyamine intake increases blood polyamine concentrations. J Nutr Sci Vitaminol (Tokyo). 2009 Aug;55(4):361-6. doi: 10.3177/jnsv.55.361.
- Muñoz-Esparza NC, Latorre-Moratalla ML, Comas-Basté O, Toro-Funes N, Veciana-Nogués MT, Vidal-Carou MC. Polyamines in Food. Front Nutr. 2019 Jul 11;6:108. doi: 10.3389/fnut.2019.00108
- Wirth M, Benson G, Schwarz C, Köbe T, Grittner U, Schmitz D, Sigrist SJ, Bohlken J, Stekovic S, Madeo F, Flöel A. The effect of spermidine on memory performance in older adults at risk for dementia: A randomized controlled trial. Cortex. 2018 Dec;109:181-188. doi: 10.1016/j.cortex.2018.09.014.
- Schwarz C, Benson GS, Horn N, Wurdack K, Grittner U, Schilling R, Märschenz S, Köbe T, Hofer SJ, Magnes C, Stekovic S, Eisenberg T, Sigrist SJ, Schmitz D, Wirth M, Madeo F, Flöel A. Effects of Spermidine Supplementation on Cognition and Biomarkers in Older Adults With Subjective Cognitive Decline: A Randomized Clinical Trial. JAMA Netw Open. 2022 May 2;5(5):e2213875. doi: 10.1001/jamanetworkopen.2022.13875
- Pekar T, Bruckner K, Pauschenwein-Frantsich S, Gschaider A, Oppliger M, Willesberger J, Ungersbäck P, Wendzel A, Kremer A, Flak W, Wantke F, Jarisch R. The positive effect of spermidine in older adults suffering from dementia: First results of a 3-month trial. Wien Klin Wochenschr. 2021 May;133(9-10):484-491. doi: 10.1007/s00508-020-01758-y
- Union list of novel foods - European Commission (accessed on 07 January 2025). Available online: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32017R2470
- Keohane P, Everett JR, Pereira R, Cook CM, Blonquist TM, Mah E. Supplementation of spermidine at 40 mg/day has minimal effects on circulating polyamines: An exploratory double-blind randomized controlled trial in older men. Nutr Res. 2024 Dec;132:1-14. doi: 10.1016/j.nutres.2024.09.012
