Companies are advertising D-aspartic acid to fitness enthusiasts and men with low testosterone and fertility problems. However, does D-aspartic acid (D-asp) have some science-based advantages or are data on its consequences and side effects completely lacking? Keep Reading to find out about the science supporting D-asp as a nutritional supplement.

What’s D-Aspartic Acid?


Aspartic acid (Asp) is an amino acid that creatures and humans naturally make in two kinds: L–Asp and D–Asp. Since our bodies can make aspartic acid, it is a non-essential amino acid. L-Asp combines with other amino acids to make proteins vital to life. D-Asp exists freely as little individual molecules in various animal and human cells.

Individual L-Asp and D-Asp molecules are made of the same atoms. In fact, they share the exact same chemical formula (C4H7NO4). The main distinction is the way they align in distance: L-Asp and D-Asp molecules are mirror images of one another, like your left hand and your right hand. These”mirrored” arrangements provide L-Asp and D-Asp different properties.

D-Aspartic Acid: Does It Boost Testosterone?

What we now know about the consequences of D-Asp made by our bodies comes from animal research. Free D-Asp occurs naturally in hormone and nerve cells in both animals and people.

D-Asp is essential for brain and nerve development and nerve communication. In addition, it helps release and produce various hormones. But, scientists are still discovering all the ways in which D-Asp affects humans.

D-Asp supplements haven’t been approved by the FDA for clinical use. In general dietary supplements deficiency strong clinical study. Regulations set manufacturing criteria for supplements, however, don’t guarantee that they are effective or safe. Speak with your physician before supplementing.

Additionally, no correct clinical studies on D-Asp for a supplement have been completed. Therefore, the potency and safety of the compound stay unknown. We recommend utilizing D-asp until appropriate clinical information is printed.

D-Asp is the common type of aspartic acid, a nonessential amino acid created by our own bodies. Scientists suspect it is essential for nerve health, but we know little about its consequences.

Mechanisms of Action

Effects on the Brain

High D-Asp levels encourage proper brain development prior to and immediately after birth. These amounts later diminish, but D-Asp proceeds to spark nerve development, helping to create awareness of their surrounding environment in adult mice.

Scientists believe D-Asp a neurotransmitter: It helps to produce or improve nerve signals, stimulates new brain links, shop memories, and promotes learning in mice.

Although naturally generated aspartic acid is required for proper brain growth, some animal studies warn us about the possible risks of bettering.

In mice, both glutamate and aspartic acid can cause brain damage and impair learning. These so-called excitatory amino acids damaged the hypothalamus, an important brain region for hormone balance (affecting pituitary hormones) and a part of the limbic system involved with emotional control.

The above studies do not refer to the D form of aspartic acid especially. The L and the D form of this amino acid may have distinct consequences. The term”aspartic acid” can typically refer to a mix of the two. The kind used to create proteins taken in from food is the L variant. In reality, L-aspartic acid can combat the ramifications of D-aspartic acid. And in 1 study, L-Asp especially had toxic effects on the kidneys and salivary glands. It is important to get these conflicting consequences in mind.

Nevertheless, research is sparse and it is unknown if D-Asp supplementation can lead to brain damage in humans; a warning is advised.

The D-Asp our bodies produce is thought to encourage brain development. On the flip side, D-Asp supplementation in animals appears to be harmful. Human data are missing.

Hormonal Effects

D-Asp stimulates the production of hormones like testosterone, progesterone, luteinizing hormone (LH), oxytocin, prolactin, growth hormone, and others involved with muscle growth, sexual performance, reproduction, and blood pressure in mice. These effects have not been studied in humans.

Claimed Health Benefits of D-Aspartic Acid

Possibly Ineffective for Increasing Testosterone

Many sources assert testosterone-fostering skills for dietary supplements containing D-Asp.

Studies show that D-Asp supplements improve testosterone levels in men creatures. However, scientific evidence for such effects in humans is weak, rare, and inconsistent.

At a 12-day, controlled research, taking 3.12 g of D-Asp daily increased testosterone levels in 23 men. All were healthy, failed no immunity training, also had reduced first testosterone levels.

Conversely, in a 14-day study of 24 healthy men, taking 6 grams of D-Asp daily greatly decreased testosterone. All guys had at least 2 decades of resistance-training and resistance-trained for 4 times in both weeks.

During a 12-week study of 19 healthy, resistance-trained men, those ingesting 6-grams of D-Asp supplement daily experienced no differences in muscle size or strength gains compared to others. None had testosterone changes. All men had at least 2 decades of resistance-training and resistance-trained for 4 times per week.

In a 28-day analysis of healthful, resistance-trained men, 3-grams of D-Asp daily did not affect resistance-training, muscle gain, or testosterone levels.

Therefore, D-Asp supplementation probably doesn’t raise testosterone levels. Future studies in healthy but comparatively inactive, non-resistance-training men are wanted. Likewise, studies of women are needed to ascertain the hormonal effects of D-Asp supplementation.

Insufficient Evidence for Enhancing Sperm Quality

Some companies are claiming that consuming D-Asp nutritional supplements or D-Asp-rich foods greatly increases male fertility. That is based on the misconception that D-Asp supplements increase testosterone.

It is true that D-asp made by the body increases levels of testosterone and other sex hormones in male animals. It has never been shown in humans. What’s more, supplemental D-asp–as explained above–most probably has no impact on testosterone levels.

On the other hand, scientists speculate that naturally occurring D-Asp controls the evolution of healthful, fully-functional sperm necessary for reproduction. For example, a study in male rabbits, a mix of L-Asp and D-Asp per day for 2 weeks increased the amount, speed, and freedom of the semen.

In 1 study, infertile men had much lower levels of D-Asp in mature sperm (if present) and semen than fertile men according to a research of 10 fertile and 20 infertile men. The effects of supplementation weren’t investigated in this study.

In another small study, carrying D-Asp food supplements (2.66 grams D-Asp per day ) for 90 days increased sperm count and enhanced sperm swimming abilities in 60 men with low sperm count and/or poorly-swimming sperm. Additionally, 26 female spouses of these men became pregnant.

But, large-scale studies are needed to determine if D-Asp dietary supplements influence infertility in men.

Uses Lacking Proof:

No clinical evidence supports using D-Asp for any of the conditions listed in this section.

Below is a summary of the present creature and cell-based research, which ought to guide additional investigational efforts. On the other hand, the studies listed below shouldn’t be interpreted as supportive of any health benefit.

IVF Research

In-vitro fertilization (IVF) clinics seek new, more efficient and reliable techniques to determine and increase the quality of egg cells in potential mothers. Such methods decrease the number of fertilized embryos required for a successful pregnancy. They also decrease the need to store embryos for longer time intervals.

In a study of 20 women (ages 22 to 40 years), concentrations of D-Asp in follicular fluid fell with aging. This decline in D-Asp is linked to decreasing quality and reduced numbers of successful pregnancies for aging women.

Egg quality may be affected by D-Asp occurring naturally in the follicular fluid which surrounds, protects, and nourishes egg cells in the ovaries. D-asp can improve egg quality by influencing growth hormone, prolactin, estrogen, progesterone, nitric oxide, amino acids, and proteins.

1 study suggests that treating semen with the mix of D-Asp, magnesium, and CoQ10 (coenzyme Q10) discovered at a popular nutritional supplement enhances the swimming and motion capacity of humans (as well as bull) sperm used for IVF (in-vitro fertilization). This therapy may also prevent damage to sperm DNA and lipids through IVF. Further research is required.

IVF research utilizing D-Asp is still in the early stages. No conclusions could be drawn from the available evidence.

D-Asp has been investigated for enhancing the quality of eggs and sperm used in IVF, but it’s too premature to draw any conclusions.

Anti-aging Research

Amounts of naturally-occurring D-Asp increase as people age in various human tissues and organs, such as teeth, bones, eyes, and brain. This is because organic L-Asp is switched to D-Asp over time. Such changes are used to understand aging, and although more research is needed, monitoring D-Asp may turn out to be helpful in anti-aging research.

Nootropic Potential

In mice studies, free D–Asp boosted brain cell communication and memory. One human study also connected increased amounts of a molecule (DAO) that alters many D-amino acids using enhanced memory and thought processes. This is compared with studies demonstrating that L-Asp can damage the brain and impair learning.

D-amino acids changed by DAO behave similarly to D-Asp. Some scientists hypothesize that D-Asp may act as a naturally occurring nootropic, although their theories remain unproven.

Some scientists consider D-Asp might have anti-aging and nootropic possible, but this has not yet been proven.

D-Asp Side Effects, Safety & Precautions

Clinical studies did not report side effects of dietary D-Asp supplements in 2.66 — 6.00 g each day. But, no proper safety studies are carried out. The brief – and long-term unwanted effects of D-Asp are still unknown.

The normal dosage recommended by manufacturers is ~3 g/day. The safety of consuming more than 6 grams daily is also unknown.

In 1 study, 6 grams of D-Asp per day for two weeks decreased testosterone amounts in resistance-trained men consuming.

2.66 g of a D-Asp nutritional supplement per day for 90 days has been safe for men with impaired fertility, as shown by a limited, small study.

In mice, aspartic acid caused brain damage and impaired learning. The consequences of D–Asp — or the D form of this amino acid specifically on the brain — isn’t well known. Past studies have shown the L-Asp can be toxic to the kidneys and adrenal glands as well. Considering that the clinical trials about the safety and efficacy of D-Asp are limited, we urge caution. The dangers can grow with higher doses and long-term usage.

D-Asp dietary supplements aren’t recommended in women and children due to a lack of security data.

D-Asp supplement labels say that use isn’t recommended in pregnant or nursing women, persons under the age of 18, or children. Some state that no women whatsoever should have D-Asp dietary supplements.

Consult your physician before using D-Asp dietary supplements.

The safety and side effects profile of D-Asp in people is unknown. Caution is advised since D-Asp had toxic effects in animal experiments.

Limitations and Caveats

Clinical trials on D-Asp are largely small scale and low quality. Additional research about the effects and safety of D-Asp in various populations is needed.

Limitations comprise :

People differ significantly from animals utilized to mimic living processes; findings from animal studies cannot be assumed to have the same effects in people.

While animal models give an overall indicator of how D-Asp nutritional supplements and natural D-Asp function in humans, future studies may reveal differences in humans.

However, little is known about amino acids in general, in contrast to their more prevalent L forms. This is an emerging area of research. Up until recently, the presence and relevance of D-amino acids have been largely downplayed.

Most human research involves quite small groups of individuals with limited diversity for important factors such as age, race, and sex. Studies of considerably larger human populations with higher demographic diversity are essential to confirm and expand the study described in this report.

Very little research was done about the role of naturally–occurring D–Asp in girls. Less research exists about the use of dietary D-Asp supplements in girls. Therefore, extensive research is still needed on large, diverse groups of girls to validate the functions of dietary D-Asp nutritional supplements and naturally-occurring D-Asp in women.

More studies involving girls from various demographic backgrounds are needed to demonstrate how D-Asp affects female fertility. Caution must be utilized in extending conclusions from research in men to D-Asp function in girls.

Drug Interactions

Research D-Asp interactions with drugs and medications are lacking. However, the following Ought to Be noted:

To shield against undesirable medication interactions, persons contemplating the use of D–Asp dietary supplements should consult their doctors regarding their health condition and possible interactions between D–Asp and their medications.

According to DrugBank (a detailed, online scientific database), drug interaction information for D-Asp is”Not Available”.

D-Asp Natural Resources, Supplementation & Dosing

Food Sources

Could you buy D-Asp from meals? The easy answer is: probably not. Aspartic acid naturally occurs in foods mainly only as L–Asp. Resources of L aspartic acid comprise turkey, eggs, legumes, avocado, asparagus, molasses, oysters, sausage, beef, poultry, kidney beans, peanuts, green beans, yellowtail fish, catfish.

L–Asp and other L–amino acids found in large quantities in food can possibly be converted to their D–amino acid kinds by cooking, modern food preparation processes, or microorganisms.

These conversions are influenced by time, temperature and pH. Overall, it seems that cooking and other food preparation process growth amounts of D-Asp in many foods. The precise ways in which the L forms can be concentrated in meals will need to be researched in much more detail.

There are no known food resources of D-Asp.

Dietary Supplements

D–Asp supplements occur as D-aspartic acid or D-aspartate (salt of D-Asp) forms commonly sold as pills, capsules, or powders. Data are lacking to ascertain if any of these forms provide benefits.

Some D-Asp supplements contained metal (calcium or zinc) chelates. These chelates are promoted as improving the body’s absorption of D-Asp. The evidence doesn’t back up such claims.

A wide selection of D-Asp dietary supplements exist. Some combine D-Asp with other possible testosterone boosters, vitamins and/or other active ingredients. Others listing D-Asp as the only active ingredient.

Some supplements contain combinations of L- and – D-Asp. Others simply contain the L-Asp form. Be wary of the fact that L-Asp may not have exactly the same consequences as D-Asp within the body.


Because D-Asp isn’t accepted by the FDA for almost any condition and clinical studies are sparse, there’s absolutely no official dose.

Studies addressed in this article used 2.66 g to 3.00 g every day in men.

Many brands and forms of D-Asp dietary supplements are commercially available. Depending upon the form and brand, most products list doses involving 3.00 g to 3.20 grams. All insist the labeled with daily dosage shouldn’t be exceeded.

User Experiences

Consumers report various experiences with D-Asp dietary supplements. Some describe having increased libido and energy levels, but also a couple of headaches when first taking D-Asp.

Some guys cite fertility improvements, but also complain of greater stress and depression. Another often-reported effect was increased strength/energy, but using some gut difficulties and poor taste.

A small number of users reported no negative results but felt no more substantial testosterone benefits.

In general, customer reviews appear neither overwhelmingly positive nor negative. Many approaches vary with the brand and type (tablet, capsule, or powder, etc) used.

The opinions expressed in this section are solely those of the users that might or might not have scientific or medical training. Their testimonials don’t represent the opinions of us. We do not endorse any specific solution, service, or treatment.

Do not consider user adventures as medical advice. Never delay or disregard seeking professional medical advice from your health care provider or another professional health care provider because of something you have read on our articles. We know that reading person, real-life encounters can be a very helpful resource, but it is not a replacement for professional medical advice, diagnosis, or treatment from a qualified health care provider.


D-Asp is the less common (“D”) type of aspartic acid, a non-essential amino acid created by our own bodies. The more common form that’s also found in food is called D-Asp.

Scientists assume that D-Asp is important for nerve health, but we know little about its consequences in people.

Small-scale human studies imply that it likely does not raise testosterone in men, but it reveals some possible against infertility. But, there is still insufficient research to urge its use for any health state.

Although D-Asp supplements are widely available and often misleadingly marketed, caution is advised. Animal studies point to D-Asp’s hazardous possible, while human security data are missing.

D-Aspartic Acid Claimed Benefits, Side Effects & Reviews