Can D-Aspartic Acid Supplements Boost Your Testosterone? Doctors Explain.

D-ASPARTIC ACID is on the long list of supplements boasting benefits ranging from boosting testosterone levels to improving fertility to beefing up your muscles. But is there any truth to these claims?

It’s hard to say since the supplement hasn’t been “well-studied,” says Danielle Velez Leitner, M.D., director of men’s health and assistant professor in the Division of Urology at Rutgers Robert Wood Johnson Medical School.

Still, Dr. Velez Leitner says taking D-aspartic acid supplements likely isn’t harmful—it just may not offer the benefits that the products claim.

Here’s what D-aspartic acid supplements can, and can’t, do.

What is D-aspartic acid?

D-ASPARTIC ACID IS a type of aspartic acid, which is an amino acid (or type of protein) that occurs naturally in your body and plays a role in your central nervous and endocrine systems, including the testicles, says Akhil Muthigi, M.D., a urologist specializing in male fertility at Houston Methodist.

A function of D-aspartic acid is to produce and release hormones in the body. That includes testosterone. Dr. Velez Leitner says, “That’s probably where a lot of the interest comes from in the supplements.”

Can D-aspartic acid supplements boost testosterone?

“THERE’S A LOT of conflicting evidence,” on whether taking D-aspartic acid supplements boosts testosterone, Dr. Velez Leitner says.

Animal studies and research using cell cultures have shown that D-aspartic acid supplements may enhance testosterone levels. One study showed that supplementing the amino acid increased blood testosterone levels in rodents.

Similar studies in humans haven’t produced the same results. “Unfortunately, most of the studies in humans regarding D-asp have been low quality with inconsistent methods, small sample sizes, and very short duration of D-asp supplementation prior to assessing the outcome.”

For instance, one small study involved 23 healthy men who took D-aspartic acid supplements for 12 days and another 2src who took a placebo. Most of the men taking the supplement saw their testosterone levels rise. However, other human research has shown mixed results—with some seeing increases in their T and others not.

More studies on men are needed to determine the impact of D-aspartic acid supplements, including whether it has a major effect on testosterone and fertility, and if those effects have long-lasting outcomes, adds Dr. Muthigi.

“I wouldn’t hang my hat on this being the golden ticket,” Dr. Velez Leitner says. “We have other, better-vetted ways of getting you to your optimal health.”

Do D-aspartic acid supplements offer other health benefits?

SOME EVIDENCE SUGGESTS that D-aspartic acid may enhance fertility by increasing testosterone levels, sperm count, and sperm motility, Dr. Muthigi says.

More research on this connection is also needed. The evidence is promising, however.

One study published in 2src17 examined the effects of a formulation of zinc, D-aspartic acid, and Coenzyme Q1src on sperm motility. It found the combo of supplements improved sperm motility.

Another study suggested that D-aspartate supplementation for 9src days improved sperm concentration and motility in 3src men who had a baseline of low sperm concentration and motility. Other research has shown the supplement can improve sperm counts.

Because D-aspartic acid may help boost testosterone, some claim it can also increase muscle mass and strength for men who work out. But, research mostly suggests the supplement isn’t effective in improving training outcomes.

Both men who took a placebo or D-aspartic acid for 28 days while they did resistance training saw similar increases in lean muscle mass, a study from 2src13 found.

Are there any risks to taking d-aspartic acid supplements?

HUMAN STUDIES ON D-aspartic acid supplements haven’t reported any evidence of serious side effects, Dr. Muthigi says. There were, however some mild ones, including irritability, nervousness, rapid heart rate, and headaches.

Keep in mind that supplements aren’t regulated like prescription or over-the-counter medications, Dr. Velez Leitner says. So, you don’t always know what fillers or other ingredients are included in the products or what the long-term effects may be.

Should you try d-aspartic acid supplements?

TAKING D-ASPARTIC SUPPLEMENTS is likely safe for most men, Dr. Velez Leitner says. But there’s little evidence that they will improve your testosterone or fertility, so talk to your doctor to determine if you really need it, and if it’s safe for you.

The amino acid is also available in foods like avocados, asparagus, lentils, leafy green vegetables, strawberries, eggs, and meat, Dr. Muthigi says. It’s healthier to get D-aspartic acid from food sources rather than supplements.

“Increasing intake via a dietary supplement may be a good strategy to ensure adequate intake in those who do not regularly consume foods high in D-aspartic acid,” he says.

If you are going to try D-aspartic supplements, Dr. Muthigi says a standard dose is 2,srcsrcsrc to 3,srcsrcsrc mg a day—but always speak with your doctor before buying any supplement. If you’re worried about your fertility or testosterone levels, they can recommend the best course of action, which may be a referral to a urologist.