This supplement’s got spunk.

Studies show that spermidine, a naturally occurring compound, can improve brain health, immunity, cardiovascular resilience and overall appearance.

“Spermidine is the Swiss army knife of longevity,” Leslie Kenny, founder of Oxford Health Span and co-founder of the Oxford Longevity Project, told The Post.

And while natural sources of it include — as the name suggests — sperm, it can also be found in breastmilk as well as foods like wheatgerm, soy beans, mature cheeses, mushrooms and peas.

Spermidine it plays a key role in slowing aging, protecting against disease, fighting inflammation and maintaining metabolism by activating a process that gets rid of damaged cell parts and recycling them.

“It’s in huge amounts in semen,” Kenny explained. “It’s in the endosperm of all seeds to ensure the survival of the next plant generation. It’s made in our tissues and our gut biome for a reason, and plants are making it for a reason too.”

Exercise, fasting, pregnancy or acute infections can ramp up levels in the boy — but our natural production plummets as we age.

Yet longevity experts like Kenny say incorporating spermidine-rich foods and spermidine supplements can keep our minds sharp, skin supple and hearts kicking.

Unsurprisingly, spermidine is a key component in biohacker Bryan Johson’s daily anti-aging regimen.

Kenny, who battled autoimmune conditions and rheumatoid arthritis in her 30s, was introduced to spermidine through researchers at Oxford University, whose work demonstrated that it could rejuvenate the immune systems of mice.

“If the immune system works, it can protect us from cancer, pathogens and an autoimmune attack. Spermidine is helpful for autoimmune patients because it’s very anti-inflammatory,” she explained.

Chronic inflammation is associated with diabetes, heart disease and muscle pain, so reducing it could yield several health benefits.

Supplementing with spermidine could also clear toxic proteins such as amyloid-beta and tau, the accumulation of which can lead to Alzheimer’s disease.

A 2023 study dubbed spermidine “groundbreaking” for hormonal health and fertility, as research showed it improved egg quality in older mice.

The same study showed that it can aid in hormone balancing and incontinence. In nearly all test subjects who took spermidine supplements, levels of the stress hormone cortisol dropped dramatically, and in male participants, testosterone increased by 50%.

“Spermidine is the trash man. If you aren’t taking the trash out, it just accumulates, nothing functions, and that’s how it is with the brain.”

Leslie Kenny

“In women, progesterone, estrogen and testosterone increased, as did the hormone precursors DHEA and pregnenolone,” Kenny said.

“Some of the women actually reported that their incontinence, that urgency to go to the bathroom, significantly reduced. I think the reason why is that faster cell turnover helps the lining of the bladder.”

That same rapid cellular turnover directly benefits hair, skin and nails.

The natural color of our hair comes from melanin. As we grow older, we make less melanin — and hence, less hair pigment. Over time, that leads to gray or white hair. 

Spermidine, however, keeps the hair follicle in the growth phase of the hair life cycle for longer, leading to longer locks and fewer grays.

A 2020 study found that spermidine supplementation protects the brain from neurodegeneration, cognitive decline, memory loss and motor impairment associated with aging.

“Spermidine is the trash man. If you aren’t taking the trash out, it just accumulates, nothing functions, and that’s how it is with the brain,” Kenny said.

In a 2018 study, spermidine improved heart function in mice, leading to better health and expanded lifespan. Similar effects have been studied in humans.

“We have these cells called cardiomyocytes that govern the rhythm of the heart, and they don’t replenish very easily,” said Kenny, who added that spermidine can help them stay in “tip-top performance condition.”

NAFLD is marked by excess fat in the liver of people who consume little or no alcohol. The primary cause is obesity, along with metabolic risk factors such as type 2 diabetes, high blood pressure, high cholesterol and obstructive sleep apnea.

In preclinical trials and animal studies, notes Kenny, spermidine reverses the effects of NAFLD.

“It’s improving metabolic function and reducing triglycerides, and it seems to help with LDL cholesterol as well,” she said.

The minimum effective dose of spermidine is one milligram per day, according to Kenny, a level that can be tough to reach through diet alone.

“It’s hard to guarantee that you get that amount from food sources, but supplementation guarantees you’re getting the right amount to help with memory and cognition. But I still want people to turn to plants if they can, because the fiber is really valuable,” she said.

The spermidine sold through the Oxford Longevity Project is plant-derived and naturally sourced, making it a cleaner and safer choice than synthetic options.

Regarding whole plant sources, mushrooms and legumes are rich in spermidine, and to a lesser degree, spinach and broccoli.

A 2016 study published in the journal Nature Medicine reported that eating aged cheese that contains spermidine was linked to a longer life span in lab mice, suggesting you don’t have to choose between eating rich and living long.

As far as getting spermidine from human sperm itself — if you’re so inclined — Kenny notes that the levels in sperm vary, and quality is dependent on the overall health of the male in question.

“It’s the fountain of youth! From a healthy man, you’d get a lot, and it would be, in my opinion, very beneficial.”