D-Aspartic Acid & Testosterone: Top 5 D-Aspartic Acid Supplements

Testosterone plays an important role in building muscle mass and strength. From improving your sex drive to controlling weight and increasing energy, testosterone plays many important roles in the healthy functioning of the human body. Low testosterone levels can result in a lack of sexual desire, low energy, problems in muscle gain, obesity, and even depression.

If you are on a quest to boost your testosterone levels naturally, take a good look at D-Aspartic acid. In recent times, the role of D-Aspartic acid (an amino acid) in boosting testosterone levels in the body has been studied and analyzed extensively.

Let us take a closer look at what this amino acid is, and scrutinize the studies that have mapped its effect on testosterone levels. We will also take a look at some of the best D-Aspartic acid supplements and consider their pros and cons, before exploring other benefits as well.

What is D-Aspartic Acid?

Aspartic acid is an amino acid found commonly in mammals and is used for the biosynthesis of proteins in the body. It is known to play a vital role in the urea cycle. Although it can be synthesized in the human body, some sources of aspartic acid are oysters, meats, sprouting seeds, oat flakes, avocado, molasses from sugar beets etc. Since it can be produced by the human body when needed, the amino acid is classified as a non-essential amino acid.

Every amino acid occurs in two different forms, which is decided by their physical composition (since they have the same chemical compositions, they occur as mirror images of each other). Aspartic acid is found in L-Aspartic acid and D-Aspartic acid, or informally called, ‘left-handed’ and ‘right-handed’ aspartic acid.

L-Aspartic acid is produced naturally in the body and is used in the synthesis of proteins. D-Aspartic acid, on the other hand, is used to produce and release hormones in the human body. D-Aspartic acid, also called D-AA, can thus, regulate hormone production.

What interests us is the discovery that D-Aspartic acid regulates testosterone levels in humans. As a result, it is used in many supplements that enhance testosterone levels in the body.  It has shown results in helping infertile men, athletes and sportsmen to improve their testosterone levels.

Summary: D-Aspartic acid is an amino acid produced naturally in the body. It regulates production of various hormones, including testosterone.

The Effect of D Aspartic Acid on Testosterone Levels

The scientific, medical, and fitness community has taken a special interest in D-Aspartic acid due to its testosterone boosting abilities. Although more rigorous and reliable studies are required to further understand the effect D-Aspartic acid supplements have on testosterone levels, the ones conducted up until now confirm a few things. Let us attempt to understand a few of them.

Many studies have been conducted to establish the effects of D-Aspartic acid on the body and if it helps in improving testosterone levels. One of the studies showed a significant increase in testosterone levels of 20 men in the sample size of 23. These men were given the D-Aspartic rich supplement for 12 days and their testosterone levels increased by 42% on average. Another study indicates that sustained consumption of D-Aspartic acid supplements might result in higher testosterone levels. Conducted with men aged between 27-43 years, the study found an increase of 30-60% in testosterone levels if taken for 90 days.

However, not all studies and trials have shown similar results. For instance, research which was undertaken with overweight and obese men had mixed results. While some of the participants in the study did not respond to the supplements, others with relatively low testosterone levels saw a jump of over 20%.

It is important to note that the studies mentioned above did not take into consideration the fact if the people who were part of the study were physically active or not. One study that factored this as well found that there was no increase in testosterone in young adults who took D-Aspartic acid and performed weight training simultaneously. Another study found out that a high dosage of 6 grams for 2 weeks actually led to a decrease in testosterone in young men who weight trained.

Summary: D-Aspartic acid leads to an increase in testosterone in specific cases like inactive men and those with low testosterone levels, but it might not necessarily show any result when these variables are changed.

How D-Aspartic acid Supplements Benefit Bodybuilders

Bodybuilders use D-Aspartic acid supplements because of its ability to boost testosterone levels. The rise in testosterone levels enhances blood circulation and increases energy.

Increased energy levels: An increase in testosterone leads to an increase in endurance power of the body while exercising, thereby increasing and improving the performance while exercising or playing sports.

Better sleep: An increase in testosterone levels seem to promote sleep quality. This helps the body to recover faster from workouts and you feel more energetic and refreshed in the morning.

Enhances blood circulation: Testosterone leads to an improved red blood cell concentration thus increasing the oxygen delivery to your muscles. This results in increased endurance during workout and enhances muscle building.

3 Additional Health Benefits of D-Aspartic Acid

In addition to helping improve testosterone levels, D-Aspartic acid is also said to offer the following health benefits:

D-Aspartic Acid May Improve Sperm Quality

A 2012 Italian study found that regular consumption of D Aspartic acid for 90 days by men with infertility problems led to increased sperm production. The trial included 30 men affected by oligo-asthenozoospermia and another group of 30 men affected by asthenozoospermia.

The daily doses of sodium D-aspartate significantly increased the concentration and motility of their sperm. These observations are backed by the fact that the rate of pregnancies increased in the partners, with 27% of them becoming pregnant during the study period.

Summary: D-aspartate significantly increases the concentration and motility of sperm.

D-Aspartic Acid Can Enhance Cognition

A study where a controlled dosage of D-Aspartic acid was administered for a time period of 12-16 days on rats, the researchers found that it enhanced neuro-related functions in their study subjects. It increased the rat’s ability to perform, and they showed a decrease in time required to complete the Morris Maze test by finding a hidden platform in lesser time.

The study could not establish any significant side effects on the rats even after the treatment was given for almost a month. Relevant human studies are yet to be conducted, but there is a distinct possibility that D-Aspartic acid supplementation can enhance our cognition and ability to focus on tasks.

Summary: Studies conducted on rats have shown that D-Aspartic acid supplementation enhanced their cognition and ability to focus on tasks.

D-Aspartic Acid May Improve Muscle Mass

Numerous studies have been conducted to study the effects of D-Aspartic acid on muscle mass and they have given varied results. One study conducted on men who took the Aspartic acid for 28 days and weight trained simultaneously noted a 2.9-pound increase in lean mass.

However, it has also been found that people who have not taken D-Aspartic acid but have weight trained have also been reported to gain the same muscle mass as those who have consumed the supplement. Several studies are still being undertaken to reach a definite conclusion on the effect that consuming D-Aspartic acid has on muscle mass.

Overall, it seems that D-Aspartic acid can help increase testosterone and improve the quality of sperm. However, it does not appear to aid muscle gain when weight-training is undertaken while consuming supplements. While doses of 2-3 grams are considered to be effective for individuals who are naturally testosterone-deficient, there is no definitive study on the side effects of taking D-Aspartic acid, if any.

To conclude, D Aspartic acid does influence testosterone levels in humans and has proven beneficial for infertile and aged men. While some studies have given mixed results, many have proven the importance of D-Aspartic acid in testosterone regulation. As science and medicine continue to find new evidence and linkages between the two, it is best to take D-Aspartic acid supplements under the guidance of trained physicians and stick to the prescribed daily dosage.

Summary: D Aspartic acid supplementation may increase lean muscle mass. More studies are needed to confirm this.

Top 5 D-Aspartic acid Supplements

Now that the importance of D-Aspartic acid has been established, and its intricate linkage with testosterone levels in the human body is being explored further, let us review some of the most prominent D-Aspartic acid supplements available today:

Bulk Supplement’s D-Aspartic Acid

Bulk Supplement%E2%80%99s D Aspartic Acid

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Bulk Supplements is a leading name in the supplementary industry and is known for producing powerful health supplements for a variety of purposes. Bulk Supplements’ D-Aspartic acid supplement is one of the most potent and reliable DAA supplements available in the market.

This supplement is free of sugar, soy, dairy, corn, yeast, additives, and gluten as well. The best part is that the supplement is available in the form of powder, gelatine capsules, and vegetarian capsules as well. The vegetarian capsules are also kosher, halal, and vegan certified.

Although DAA is a non-essential amino acid, it helps in the synthesis of Luteinizing Hormone (LH), which supports the production of testosterone and thus, helps you improve energy levels, improve your sexual health, increase libido, and also support the brain function. DAA supplements are also known to improve athletic performance.

The recommended dosage is between 2500 mg to 3500 mg in one serving, ideally with the first meal of the day. You can blend the powder with your morning smoothie or take it with water as well, or simply consume the capsules, if that’s your preference.

If you are taking capsules, then stay clear of the capsules with gelatin-based covers and opt for the vegetarian ones. It is also recommended that the supplement not be consumed for more than eight continuous weeks. Take a break of at least four weeks before starting again.


  • Available in several easily digestible forms
  • Free of sugar, dairy, corn, yeast, soy, and gluten
  • Vegetarian capsules available
  • Cost-effective


  • Has a slightly bitter aftertaste
  • May cause diarrhea

Nutricost D-Aspartic Acid Capsules

Nutricost D-Aspartic Acid

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Nutricost is known for its quality and affordable health supplements in the fitness industry. Nutricost’s high-quality DAA supplements come in an encapsulated form. The capsules are gluten-free, non-GMO, and have been tested by third parties as well. Nutricost manufactures the supplement in GMP-compliant and FDA-registered facilities. Thus, the company ensures that their supplements are of the highest quality and are suitable for people with allergies and intolerance to gluten.

D-Aspartic acid is known to support the production of testosterone and can help men boost flagging energy levels, enhance sexual health and desire, and also better physical performance. Thus, men, particularly older men, should consider taking these supplements after consulting their physicians. The supplement has helped countless men fight age and hormone-related challenges and is one of the most personally-recommended products in the market.

Nutricost’s D-Aspartic acid supplements come in a packaging of 180 gelatinous capsules of 750 mg each and the daily recommended dosage is 3000 mg (4 capsules). Thus, you will be able to get 45 servings from a single bottle of these supplements. You can take the capsules with some water in the morning. Since the capsules are odorless and tasteless, they can be ingested easily.


  • Gluten-free and non-GMO
  • Third-party tested
  • Manufactured in GMP-compliant and FDA-approved facilities
  • Easy to swallow


  • May trigger headaches
  • Priced higher than other similar supplements

Athletic Xtreme D-Aspartic Acid Capsules

Athletic Xtreme D Aspartic acid

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One of the purest and most powerful D-Aspartic acid supplements available, the Athletic Xtreme D-Aspartic acid capsules are natural testosterone boosters that come with a guarantee of the purity. The supplements are manufactured in Canada and are tested in a laboratory to ensure the highest quality of D-Aspartic acid.

D-Aspartic acid is known the help boost testosterone levels and help men in improving their energy levels, libido, and cognitive functioning. Athletic Xtreme says that D-Aspartic acid supplements improve testosterone levels in two ways. One, by releasing Luteinizing Hormone (LH) and two, by increasing metabolic activity in testes. The brands also say that D-Aspartic acid has been clinically tested to improve the production of testosterone.

They further explain that the study found that even after the discontinuation of the supplement, the testosterone levels remained elevated for a few days, which indicates that D-Aspartic acid accumulates over time, and gradually reduces once the supplement is stopped.

Each bottle contains 180 capsules of 500 mg each and the daily recommended dosage is 3000 mg. Thus, you are required to consume six capsules each day (three capsules twice) and the bottle will easily last you for the entire month.  The gelatinous capsules are small in size and can be consumed easily with water.


  • Lab-tested for purity
  • Highest quality of D-Aspartic acid
  • Small capsule size; easily-ingestible
  • Pocket-friendly price


  • May cause a temporary flushed feeling
  • May trigger skin rashes

Simple Organics D-Aspartic Acid Capsules

Simple Organics

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Simple Organics is one of the most reputable names in the healthcare and fitness supplement industry. Their D-Aspartic acid supplement capsules is a unique blend that can help you improve testosterone levels. In addition to improving your sexual health and drive, these supplements can also help you boost energy as well.

The capsules are 100% natural and pure as they are free of gluten, GMOs, fillers, chemicals, soy or preservatives. What’s more, they come with an assurance of quality as the supplements are 100% pharmaceutical grade and are manufactured in the USA at FDA-registered facilities.

The best part is that supplement comes with a 100% money-back guarantee and if you aren’t satisfied with the results, you can simply return the bottle and claim a refund. While the actual price of the supplement is high compared to similar products, it is usually available online with an attractive discount.

One bottle of Simple Organics D-Aspartic acid supplements contains 180 capsules, and can last nearly 45 servings. The company recommends taking 4 capsules with meals, or as directed by the physician. You must keep in mind the daily recommended value of 3000 mg while taking these supplements.


  • 100% money-back guarantee
  • Suitable for vegans and vegetarians
  • Contains no GMOs, gluten, fillers, or preservatives
  • Manufactured at FDA-registered facilities


  • Not suitable for pregnant women
  • Pricier than other D-Aspartic acid supplements

Eagleshine Vitamins Supplement D-Aspartic Acid Capsules

Eagleshine Vitamins

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Eagleshine Vitamins produces a wide range of health supplements for a variety of deficiencies and purposes. They also have D-Aspartic acid capsules that help with testosterone deficiencies and help improve libido and metabolism. The capsules have benefited countless men with infertility, low energy, low sex drive, and other age-related sexual and energy issues.

The supplements are manufactured in California, USA, and have been lab-tested by third-parties to ensure the quality and purity of the product. The capsules are non-GMO, and contain zero gluten, dairy, soy, sugar, tree nuts, or preservatives. The only ingredients other than D-Aspartic acid are rice flour and gelatin, which makes these capsules unsuitable for vegetarians and vegans. The best, however, is that the supplements come with a 60 days money-back guarantee. The supplement is easily available online and offline as well.

The recommended serving size (of 3000 mg) can be achieved by 4 of these capsules and since the bottle has 180 capsules, it contains a supply for 45 days. However, you can regulate the dosage as prescribed by your physician.


  • Free of GMOs, gluten, soy, and dairy
  • Made in USA
  • Third-party tested for purity and quality
  • 60 days money-back guarantee


  • Not suitable for vegetarians and vegans
  • You may not like the taste

Foods High in D-Aspartic Acid

D-Aspartic acid is naturally found in foods. Even if you are using supplements, make sure you include these natural sources as well into your diet to ensure you get adequate dietary protein to keep your body functioning at its best.

  • Poultry: Since muscle tissue is made up of protein, with amino acids are their building blocks, poultry and meat are great sources of protein, especially D-Aspartic acid. A 3-ounce serving of beef roast has about 2.4 grams of aspartic acid while an average-sized beef fillet offers you 4.5 grams. Roasted chicken breast contains 3.7 grams while a similar serving of turkey meat gives you only 2.8 grams of aspartic acid.
  • Egg and Dairy: a single cup of nonfat milk has 0.7 grams of aspartic acid while a boiled egg can give you 1.7 grams of the same. Butter, cream, cheese and yogurt also have this amino acid. A cup of mozzarella cheese contains 2.5 grams of aspartic acid and a cup of Parmesan cheese has 2.6 grams. Other cheese varieties such as Swiss cheese, cheddar, provolone all contain over 2 grams of aspartic acid per cup. So make sure you include plenty of dairy products in your diet along with the eggs.
  • Grains: A cup of corn has 1 gram of aspartic acid while a cup of uncooked oat bran has 1.5 grams. Parboiled, white rice also has 1.5 grams of aspartic acid per cup. Buckwheat, millet, barley and amaranth are some other good sources of aspartic acid.
  • Fruits: Bananas, plums, nectarines and cherries have 0.5 to 0.6 grams of aspartic acid per serving cup. Dried fruits such as apricots and peaches (dried) are an even better source of aspartic acid as they offer about 0.8 grams per cup.

Recommended Dosage for D-Aspartic Acid Supplements

2.6 to 3 grams per day is the dosage recommended by most studies that investigated the effects of D-aspartic acid on testosterone. If you are a beginner, then start at a low dose of 2 to 3 grams and then build up gradually to 5 to 10 grams a day. Most people get a good response at these levels.

The maximum dosage is about 20 grams though this is too high for most individuals. Lower doses of about 3 grams seem to be effective those middle-aged men who are not very active while this dose was not enough for the more active men who participated in studies on this topic.

A 2012 Italian study noted positive effects of D-aspartic acid supplementation on sperm quality and quantity at just 2.6 grams per day, when taken regularly for a period of 3 months. You can take D-Aspartic acid supplements with or without food. If you feel nausea while taking it on an empty stomach then try taking it half an hour after a light snack. If you are taking more than 5 grams then its best to split into two dosages, morning and evening.

Rather than taking it continuously, use these supplements for about 3 weeks before taking a week or two off. Cycling them will help retain their effectiveness while reducing chances of side effects.

Side Effects and Safety of D-Aspartic Acid Supplements

In the Italian study mentioned above, 30 patients with asthenospermia (reduced sperm motility) were treated with 2.6 grams/day of D-aspartic acid for 90 days. Extensive blood tests were conducted to investigate whether the participants experienced any adverse side effects. The researchers concluded that the supplement is safe for consumption as no safety concerns were observed.

Some users of D-Aspartic acid have reported headaches, nervousness and irritability while using it. Digestive disturbances, diarrhea and nausea can occur. Skin rashes may also be seen in some people.

Most of these side effects are minor and tend to vanish after the initial period. If the discomfort persists, discontinue the supplements as they may not suit you personally. Always consult a physician before starting on any such supplements, especially if you are on any other medications.

The Final Note

Many people, especially bodybuilders, are on the lookout for ways to boost their testosterone levels naturally, rather than resort to harmful steroids. D-Aspartic acid supplements are an option that should be seriously considered for raising your testosterone levels as many studies have shown that doses as low as 3 grams may increase testosterone in men.

There is evidence of improvement in sperm quality and sperm motility of men experiencing fertility issues, when they take D-Aspartic acid regularly. D-Aspartic acid also seems to have other benefits such as enhancing cognition and improving muscle mass. But more studies need to be conducted to establish all these claims.

While some users reveal they have benefited from D-Aspartic acid supplementation, others may not feel the same. D-Aspartic acid has been found to be safe for consumption for up to 90 days. Try it out for yourself and see how it works for you.


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