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What is D-Aspartic Acid? | Benefits, Side Effects & Dosage

What is D-Aspartic Acid? | Benefits, Side Effects & Dosage
Liam Agnew
Sport and Performance Nutritionist2 years ago
View Liam Agnew's profile
D-aspartic acid is a supplement often taken by men with the purpose of maintaining normal testosterone levels. The following article will explain exactly what D-aspartic acid is, how it works, the potential benefits, how much you need and any possible side effects. 

What is D-Aspartic Acid?

Primarily, D-aspartic acid is known to increase the release of luteinizing hormone in the brain, resulting in the production of testosterone.1 It is one of two forms of the amino acid aspartic acid. The other form is L-aspartate. Amino acids serve a multitude of functions in the body, but you’ll probably have come across them before as the building blocks of all types of protein, along with hormones and neurotransmitters.

D-aspartic acid works in your central brain region to cause a release of hormones, such as luteinising hormone, follicle-stimulating hormone, and growth hormone.1 It may also build up in the testicles, where it alleviates a rate-limiting step of testosterone synthesis, which leads to a minor testosterone increase.1


D-Aspartic Acid Benefits

May Boost Sperm Count Boosting Sperm Count

Males who struggle with a low sperm count may benefit from using D-aspartic acid supplementation, as research has shown that supplementation can cause a significant improvement in sperm count and motility.2

D-Aspartic Acid May Increase Energy Levels

One of the major benefits of raising levels of testosterone from below normal levels to normal levels via d-aspartic acid supplementation, is the improved production of energy, which can mean better exercise endurance and greater sporting performance.

D-Aspartic May Reduce The Impact Of Sleep Reduction

Higher testosterone levels have been touted to produce a better night's sleep. They also result in improved energy levels and better health and recovery from your last workout.Sleep restriction or low quality sleep has been shown to contribute to a reduction in testosterone as the majority of testosterone is released whilst the body is sleeping.3 In a one week study in young, healthy males, sleep reduction (5 hours a night), resulted in a drop of day time testosterone levels by 10-15%.4 If you struggle sleeping on a long term basis, you may well have lol levels of testosterone and d-aspartic supplementation may help bring them back to normal. 

Good For Your Circulation

Did you know that testosterone also promotes the body’s red blood cell concentration and helps to deliver oxygen to the muscles?5 That could mean that improving testosterone via d-aspartic acid supplementation may increase the capacity to build muscle, as well as better exercise endurance.

Find out what other supplements you should be taking to build muscle:


24-Hour Supplement Guide | What To Take To Build Muscle

Make the most out of your gym sessions by fuelling right.

D-Aspartic Acid for Bodybuilding

Arguably the most common reason for supplementing with D-aspartic acid is for bodybuilding. Natural bodybuilding requires natural testosterone boosters that are legal are in great demand in the sporting world, but especially within the weight-lifting community. As the body naturally ages beyond your twenties, the body’s ability to produce testosterone wanes. It’s known that the libido can often diminish along with a decrease in sperm count as you age, but the ability to build and keep muscle mass also, sadly, can take a considerable hit.

The good news is, it’s far from impossible to continue building muscle as you reach your 50s and 60s. As testosterone is well-known to be responsible for muscle building and libido, older people that are still keen to build muscle at the same rate they did in their younger days often use natural, legal supplements to increase the production of this important hormone. D-aspartic acid is one of these supplements that may aid the maintenance of normal testosterone levels as you get older.

Normal or high levels of testosterone improves muscle-protein production, leading to lean muscle mass development. Testosterone also inhibits the production of cortisol, which is a hormone that can result in more stomach fat and the loss of muscle tissue.

These facts, combined with the sleep-enhancing, energy-yielding results of normal or high testosterone levels, makes D-aspartic acid a potentially valuable supplement for weight lifters of all ages.

Read more about our natural ways to boost testosterone.

D-Aspartic Acid Side Effects

Having very high levels of testosterone can have some side effects. However, the growth and development of acne and hair are commonly known amongst those with very high levels of testosterone, along with elevated levels of aggression and a bigger appetite. It is unlikely that d-aspartic acid supplementation will raise testosterone levels to such an extent and currently there are no known side effects of d-aspartic acid supplementation. 

Do I need to be concerned?

D-aspartic acid is widely considered safe, and is not listed as a banned sporting substance.

In one 90-day study published by Advances in Sexual Medicine, participants took 2,660 mg of D-aspartic acid on a daily basis. Sixty men were treated and, of that number, 30 men were suffering from asthenozoospermia (reduced sperm motility), while the other 30 men were experiencing oligoasthenozoospermia (reduced sperm motility and reduced sperm count). The research measured the participants’ creatinine levels, electrolytes, blood cells, glucose, enzymes, and urea on a regular basis and found no abnormalities. The results revealed that there were no dangerous outcomes to the human body by using D-aspartic acid and that it can substantially boost the levels of luteinising hormone within the body.

D-Aspartic Acid Supplements

Our D-aspartic acid is the perfect way to supplement your diet with this bodybuilding workout supplement. For anyone who regularly engages in heavy resistance training, this easy to mix powder form of the supplement is ideal for daily use.

D-Aspartic Acid Dosage

Add your preferred amount of water or fruit juice into a protein shaker. Then add 1 1/2 small scoops (3g), shake and consume. Use once daily. After 12 days of consecutive use, we recommend taking 1 week off before repeating the cycle.



What is d-aspartic acid?

D-aspartic acid is one of two forms of the amino acid, aspartic acid. It is known to increase the release of a hormone in the brain resulting in the production of testosterone.

What are the benefits of d-aspartic acid?

The benefits of d-aspartic acid may include increased sperm count levels in males, increased energy levels, better sleep quality and improved circulation.

Should you cycle d-aspartic acid?

Yes, we recommend taking 1 week off after 12 days of consecutive use of d-aspartic acid.

How should I take d-aspartic acid?

We recommend supplementing a d-aspartic acid powder, taking 3 grams per day for 12 consecutive days, followed by a week off.

Is d-aspartic acid safe?

D-aspartic acid is widely considered safe and is not listed as a banned substance in sport.

Take Home Message

As a potential testosterone-booster, D-aspartic acid is often used by regular gym-goers and those looking to increase muscle mass, and is prescribed for men with fertility problems.



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Our articles should be used for informational and educational purposes only and are not intended to be taken as medical advice. If you're concerned, consult a health professional before taking dietary supplements or introducing any major changes to your diet.

  1. Topo E, Soricelli A, D’Aniello A, Ronsini S, D’Aniello G. The role and molecular mechanism of D-aspartic acid in the release and synthesis of LH and testosterone in humans and rats. Reprod Biol Endocrinol. 2009;7:120. Published 2009 Oct 27. doi:10.1186/1477-7827-7-120
  2. 1. D’Aniello, G., Ronsini, S., Notari, T., Grieco, N., Infante, V., D’Angel, N., … & D’Aniello, A. (2012). d-Aspartate, a key element for the improvement of sperm quality. Advances in Sexual Medicine, 2(04), 45.
  3. Axelsson J, Ingre M, Akerstedt T, Holmbäck U. Effects of acutely displaced sleep on testosterone. J Clin Endocrinol Metab. 2005;90(8):4530–4535. PubMed | Link to Article. [PubMed] [Google Scholar]
  4. Leproult R, Van Cauter E. Effect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA. 2011;305(21):2173-2174. doi:10.1001/jama.2011.710
  5. Bachman E, Travison TG, Basaria S, et al. Testosterone induces erythrocytosis via increased erythropoietin and suppressed hepcidin: evidence for a new erythropoietin/hemoglobin set point. J Gerontol A Biol Sci Med Sci. 2014;69(6):725-735. doi:10.1093/gerona/glt154


Liam Agnew
Sport and Performance Nutritionist
View Liam Agnew's profile

Liam is a certified sport nutritionist with the International Society of Sport Nutrition and is enrolled on the British Dietetics Association’s Sport and Exercise Nutrition register. He has a Bachelor’s of Science in Sport and Exercise Science and is graduate of the ISSN Diploma in Applied Sport and Exercise Nutrition.

Liam is an experienced personal trainer, helping clients reach their health and fitness goals with practical, evidence informed exercise and nutrition advice. In his spare time Liam has competed in numerous powerlifting competitions and enjoys hill walking, football and expanding his recipe repertoire in the kitchen.

Find out more about Liam's experience here.