If you look up substances that can help increase testosterone production, D-aspartic acid (DAA) comes up surprisingly often. It’s so common, in fact, that you’ll find it in most testosterone-boosting supplements as an active ingredient. 

So, does D-aspartic acid actually work? If it does, what are its actual effects on your body? And do these effects include anything concerning? Let’s find out.

What is D-aspartic acid?

D-aspartic acid is a molecule known as ɑ-amino acid, which is used for the biosynthesis of proteins. Think of ɑ-amino acids as building blocks that link with each other to form long-chain molecules. These long chains can take the form of proteins, neurotransmitters, and even hormones. 

The main role of D-aspartic acid in humans is as a hormonal regulator. It signals your brain to increase the secretion of luteinizing hormone, growth hormone, and follicle-stimulating hormone. These hormones, in turn, regulate other functions like muscle & organ tissue growth and the menstrual cycle in women.

Can D-aspartic acid boost testosterone?

Yes, it can. D-aspartic acid increases luteinizing hormone secretion, which in turn boosts testosterone production by activating the gonadal glands. It’s also an essential component of Leydig cells that are the primary source of testosterone production in men. A 2009 study by Topo et al. further solidified the effects of DAA on testosterone by giving 23 men a daily dose of D-aspartic acid supplements for 12 days. After the test period, the test subjects showed a 42% average increase in testosterone levels.

Effects on static men

A lack of activity/exercise does not seem to have any negative impact on D-aspartic acid’s effectiveness.

This is backed by a 2015 study that involved 10 obese men who did not have a workout routine or even a basic exercise regimen.

After a 28-day test period, men with low T showed a 20% average increase in their testosterone levels without any changes in their lifestyle. 

Another 2012 study by D’Aniello et al. showed a similar trend.

In this study, physically inactive test subjects displayed a 30-60% testosterone increase after taking D-aspartic acid supplements for 90 days.

Effects on men who train

Working out can boost testosterone production without any supplementation. So logic dictates that men who train will get a larger boost by including DAA supplements into their routine. Unfortunately, the truth contradicts this logic, where intense workouts like resistance training can actually nullify the benefits of DAA

An earlier 2015 study by Melville et al. went even further and showed that regular D-aspartic acid supplementation alongside weight training could even lower testosterone levels in men. It noted the effects of DAA on men who worked out four days a week. They were given 6-gram DAA supplements for a 14-day test period, and the results showed a ~12.5% decrease in T levels.

Not to be confused with L-Aspartic acid

Aspartic acid is an amino acid, and almost every amino acid occurs in two different forms. For aspartic acid, the two forms are D-aspartic acid and L-aspartic acid. Both of these amino acids have the same chemical formula but have completely different chemical properties. This is because the two differ in their molecular structure, which plays a massive role in how a molecule behaves. 

D-aspartic acid is mostly responsible for increasing the secretion of luteinizing hormone, which boosts testosterone production. On the other hand, L-aspartic acid plays a crucial role in building proteins and regulating metabolism during the energy-producing Krebs cycle.

Can it help with performance?

As we discussed earlier, resistance or strength training can actually nullify the benefits of D-aspartic acid supplementation. Because of this negative correlation, DAA has little to no effect on your workout performance. To prove this, Darryn S Willoughby conducted a study that divided men into two distinct groups. One of these groups received 3 grams of DAA before each workout session, while the other received a placebo.

After a 28-day test period which included 4 days of heavy resistance training per week, both groups showed a nearly identical increase in muscle mass and muscle strength.

Another 2017 study repeated a similar test but for a longer 3-month test period. Unsurprisingly, the results were the same as D-aspartic acid did not show any positive impact on the training outcome.

Who should take D-aspartic acid?

Men with low testosterone — who do not partake in intense workouts like strength and resistance training — should take D-aspartic acid supplements. Doing so will help boost their testosterone levels and improve testicular health. 

On the other hand, DAA is not recommended for women. Its effects on testosterone in women are still unknown due to a severe lack of academic research. That said, D-aspartic acid can improve fertility rates in women by maintaining higher-quality oocytes;, cells that form the ovum.

However, it is important to note that you might not have to take D-aspartic acid supplements. It is a non-essential amino acid that your body produces on its own.

Can it be bad for me?

Not really. As far as we know, D-aspartic acid that’s consumed through food and supplements is completely safe for men as long as they don’t take too much of it. Although, one person did report symptoms like irritability, nervousness, and headaches after taking DAA during a 2013 study. But, similar symptoms were reported by another person in the placebo group — disproving D-aspartic acid’s involvement in the matter.


D-aspartic acid appears to beappears to be a safe and effective method of boosting testosterone for men. This is because it increases the secretion of luteinizing hormone — signaling your testes to produce more testosterone. It is also an essential component of Leydig cells, the tiny biological factories that produce testosterone within the gonadal glands. 

That said, DAA is not a one-stop shop for testosterone regulation. For instance, when DAA is combined with weight training, it can actually reduce T levels instead of boosting them. So, if you’re after long-term testosterone balance, we recommend looking into other T-booster substances like Fenugreek extract, zinc, magnesium, and vitamin D.


What is the right dose for D-aspartic acid?

Unfortunately, there is no universally agreed upon “correct” dosage for D-aspartic acid. But we can derive the right amount from the research that’s been done on its effects. Studies such as the one by Topo et al. show that 3 grams of DAA is enough to boost testosterone by 42% in men who do not train. So, the ideal daily dosage of D-aspartic acid appears to be around the 3 grams range.

Can D-aspartic acid improve fertility in men?

Yes, it can. D-aspartic acid shows promising results as a probable cure for infertility in men. The aforementioned 2012 study by D’Aniello showed an increase in sperm count and quality in most of the 60 subjects. It also reported an increase in the rate of pregnancies during and after the D-aspartic acid supplementation.

Is it possible to overdose on D-aspartic acid?

Yes, you can overdose on D-aspartic acid. Unfortunately,  an overdose causes a negative nitrogen balance which can lead to issues like edema, anemia, and lowered resistance to infections.

About the Author Tim Rockwell

Tim Rockwell is a highly skilled and knowledgeable fitness expert. With a background in exercise science and years of experience in the fitness industry, Tim is passionate about sharing his expertise with others through his writing. He currently contributes articles to Eurasc, where he shares practical tips and strategies for leading a healthy, active lifestyle.

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