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Nugenix Free Testosterone Booster Review: A Dietitian’s Objective Analysis

By Sharon Lehman, RDN

Medically Reviewed by Anthony Dugarte, MD

Last Updated on May 18, 2022

Dietitian Rating:


About This Rating
The average rating of this product is calculated based on the evaluation of the following factors:
  • Support for Claims:3.0
  • Ingredient Safety:4.0
  • Value for the Price:3.0
  • Brand Transparency:3.0

Nugenix Free Testosterone Booster is a men’s dietary supplement designed to support healthy levels of free testosterone for increased libido, enhanced muscle mass, and more stamina. Some, but not all of the ingredients can back up the claims.

Written by
Sharon Lehman, RDN
Registered Dietitian Nutritionist
Sharon Lehman, RDN is a Registered Dietitian Nutritionist and writer with over 10 years of experience in the health and wellness industry. She earned her Bachelor of Science degree in Dietetics and completed her dietetic internship at the University of Delaware and a Master of Education degree from Wilmington University with a concentration in elementary and secondary school-based counseling.
Medically Reviewed by
Anthony Dugarte, MD
Medical Reviewer
Anthony Dugarte, M.D., C.S.C.S. is a health and wellness writer and medical content reviewer. In addition to dedicating the last 7 years to medical research, Dr. Dugarte also has more than a decade of experience in strength and conditioning, nutrition, and rehabilitative exercise, as well as authoring and reviewing health and wellness-related content.
Nugenix Free Testosterone Booster Review: A Dietitian’s Objective Analysis
Photo by WellnessVerge


  • Accessible at most major retailers
  • 30-day return policy
  • Relatively safe ingredients
  • Some ingredients are evidence-supported


  • Expensive
  • Lacks independent third-party testing
  • Amount of each ingredient in the testosterone complex proprietary blend is not specified

What Is Nugenix?

Nugenix is a testosterone-boosting ingredient complex designed to support healthy testosterone levels in men.

Testosterone boosting supplements, including Nugenix, claim that by bringing levels up, men will build more muscle with strength training, have increased strength, and enhanced sexual libido and performance.

Testosterone is the primary male reproductive hormone and has many functions in the body, including sexual function, reproduction, skin health, energy, mood, and brain health. (1)

It also plays a role in body composition, helping to regulate fat metabolism and muscle mass.

Men naturally experience a decrease in testosterone levels as they age, usually beginning around the age of 30. (2)

Low testosterone levels are linked to erectile dysfunction and an increased risk of serious diseases, like diabetes, heart disease, obesity, and depression. (3)

Over-the-counter testosterone boosters have gained popularity since they’re considered safer than hormone replacement therapy.

The only way for a man to know if his testosterone levels are low is through blood work.

Does Nugenix Work? Evaluation of Ingredients

The manufacturer's website lists the following ingredients present in Nugenix:

  • Vitamin B6 (as Pyridoxine Hydrochloride): 2 mg
  • Vitamin B12 (as Methylcobalamin): 50 mcg
  • Zinc (as Zinc Chelate): 1 mg

Nugenix® Free Testosterone Complex (Proprietary Blend): 2103 mg

  • L-Citrulline Malate
  • Fenugreek Extract (seed)
  • 50% Fenuside™(Testofen®)
  • Tribulus Extract fruit
Nugenix ingredients label. Photo by WellnessVerge
Nugenix ingredients label. Photo by WellnessVerge

Vitamin B6 (pyridoxine hydrochloride)

Nugenix Free Testosterone Booster contains 2 milligrams of vitamin B6 per serving. (4)

The Recommended Dietary Allowance for B6 is 1.3 milligrams per day and the Upper Limit is 100 milligrams per day.

Vitamin B6 plays a big role in energy production and protein metabolism. (5)

Most people do not need B6 supplementation and get adequate amounts of B6 from food, where it’s found in poultry, pork, fish, white and sweet potatoes, and many fruits.

Some research suggests that the need for vitamin B6 increases with exercise. (5)

Vitamin B12 (methylcobalamin)

Nugenix Free Testosterone Booster contains 50 micrograms of vitamin B12 per serving. (6)

The Recommended Dietary Allowance for B12 is 2.4 micrograms per day and no Upper Limit exists since toxicity is unlikely.

Most people get enough vitamin B12 from food, where it’s plentiful in animal foods, like meat, poultry, dish, eggs, and dairy.

Vegans and some vegetarians who don’t eat animal foods may require supplementation.

Vitamin B12 plays a role in cell production, including the creation of new red blood cells.

There is no direct link between vitamin B12 and testosterone production.

However, many energizing supplements including Nugenix, include it to enhance energy and athletic performance even though there’s no evidence to support this if your levels are normal.

Zinc (zinc chelate)

Nugenix contains 1 milligram of zinc per serving. (7)

The Recommended Dietary Allowance for zinc is 11 milligrams per day and the Upper Limit is 40 milligrams per day.

A review of research on zinc’s role in physical activity found that blood levels of zinc decreased following exercise, suggesting it plays a role in muscle recovery. (8)

There’s also some evidence suggesting a relationship between levels of zinc and free testosterone in the body.

A small study conducted on male wrestlers found levels of free testosterone increased following 4 weeks of zinc supplementation. (9)

Another study found that zinc supplementation in elderly men resulted in increase in serum testosterone after six months. (10)

Nugenix Free Testosterone Complex

The proprietary blend in Nugenix is called the Nugenix Free Testosterone Complex, which contains L-citrulline malate, Testofen, and tribulus.

The label says each serving contains 2,103 milligrams of this complex but does not list the specific amounts of each ingredient.

L-citrulline malate

Nugenix also contains an amino acid called L-citrulline malate. In the body, it’s converted to another amino acid, L-arginine, which is involved in the production of nitric oxide.

Nitric oxide plays a role in healthy blood flow by dilating blood vessels. (11)

Low levels of nitric oxide are linked to erectile dysfunction (ED). (12)

Some evidence suggests L-citrulline supplementation can improve symptoms of mild ED in men. (13)

Several studies have also looked at the effect of L-citrulline on exercise endurance and fatigue, but supplementation was not effective at improving performance for high-intensity plyometrics, upper-body resistance training, or cycling. (14, 15, 16)


Testofen in Nugenix, is a registered name for a brand of fenugreek seed extract. Fenugreek is a plant that’s used in cooking and ancient medicinal practices. (17)

There is some evidence that fenugreek seed extract improves testosterone levels, libido, and body composition in men.

A double-blind, randomized controlled trial involving 120 men found men taking 600 milligrams of fenugreek seed extract per day for 12 weeks had improvements in sexual function and testosterone compared to the placebo group. (18)

Another study involving 60 men found those who took 600 milligrams of Testofen per day had improved libido compared to the placebo group. (19)

A study of 49 men found that those who took 500 milligrams of fenugreek seed extract for 8 weeks had enhanced body strength and improved body composition compared to those taking a placebo. (20)


Testofen (or Fenugreek Extract) present in Nugenix may help improve libido and enhance body strength, according to studies.

Tribulus Extract

Tribulus also has a history of use in ancient medicine.

It’s often found in testosterone boosting supplements, even though research has mixed findings regarding its usefulness.

Several studies have found tribulus supplementation has no effect on testosterone levels or erectile dysfunction, but that it may improve libido. (21, 22)

There’s also no evidence to support its use by athletes for boosting performance or body composition. (23)

Support for Claimed Benefits

Below is our summary of the available evidence available for the claimed benefits of Nugenix Testosterone Booster:

Increase sex drive3/5
Enhance muscle mass3/5
Boost free testosterone3/5

Nugenix Dosage

The recommended dosage for Nugenix Free Testosterone Booster is 3 capsules per day taken on an empty stomach.

The instructions advise taking the supplement in the morning or 30–45 minutes before a workout.

On the product FAQ page, the brand advises supplementing with Nugenix for 8 weeks in combination with exercise.

For men who feel like they need more testosterone booster than the recommended dosage, the manufacturer says increasing the dosage from 3 capsules to 4 or 5 capsules is acceptable because it “will still be in a safe tolerance zone.”

Unless you're already aware of your current testosterone levels and whether you have any deficiencies, it's critical to speak to your medical care provider to help determine whether the ingredients present in Nugenix are safe and effective for you at the dosages the manufacturer recommends.

This is especially true since the manufacturer states that you can slightly increase your dosage.

Is Nugenix Safe?

Although the ingredients in Nugenix are probably safe for most healthy men to take without any serious risk of adverse side effects, not knowing the exact amount of the active ingredient poses some problems.

Some may experience mild digestive upset while using this supplement.

Nugenix also contains 50 mcg of vitamin B12, even though the recommended daily amount of vitamin B-12 is 2.4 micrograms. (24)

Nugenix doesn’t contain quite as much vitamin B6 or zinc, but you’ll want to check the amount of these in other supplements to make sure you’re not getting too much.

Although it’s unlikely this supplement will result in excessive testosterone, it’s a good idea to be aware of signs your testosterone levels may be too high.

Acne, voice changes, excessive body hair, male pattern baldness, and mood imbalances can result from too much testosterone. (25)

If you notice any of these changes, check in with your primary healthcare provider ASAP. 

Also, talk to your healthcare provider if you're considering trying Nugenix or any other testosterone supplement.

Nugenix Capsules. Photo by WellnessVerge
Nugenix capsules. Photo by WellnessVerge

Cost and Where to Buy

Nugenix Free Testosterone Booster costs $69.99 for one bottle directly on the brand's website. Each bottle contains 90 capsules for a 30-day supply, which equates to roughly $2.30 a day per serving.

Nugenix does back its product with a 30-day return policy when you buy it from the manufacturer's website.

Additionally, you can find Nugenix at most major retailers, including Walgreens, Rite Aid, CVS, GNC, Amazon, and Walmart.

It's about $20 cheaper if bought on Amazon or Walmart.

The Bottom Line

Research suggests that some of the ingredients present in Nugenix Free Testosterone Booster may help improve sexual function, libido, and body composition, and increase testosterone.

However, the evidence is limited and suggests short-term results.

There is no evidence that taking this product will result in long-term results.

One review found that most testosterone-boosting supplements lack evidence to support their claims, and many contain high doses of vitamins and minerals that can easily approach or exceed upper limits when combined with other supplements. (2)

If you suspect your testosterone could use a natural boost, there may be some lifestyle factors you can alter to help.

Following natural methods to boost testosterone may also help improve your overall health.

Research has found that men who are physically active, maintain a healthy weight, and eat a nutritious diet have higher testosterone levels than those who don’t. (26, 27, 28)

Other lifestyle factors, like avoiding smoking, limiting alcohol intake, and getting enough rest also play a part in maintaining healthy hormone levels. 

Check with your primary healthcare provider before trying this or any other testosterone boosting supplement.

They can check your hormone levels, which is the only way to know for sure if you have low testosterone.

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At WellnessVerge, we only use primary references for our articles, including peer reviewed medical journals or well-respected academic institutions.

  1. Revisiting the role of testosterone: Are we missing something?:
  2. ‘Testosterone Boosting’ Supplements Composition and Claims Are not Supported by the Academic Literature:
  3. Testosterone deficiency in the aging male:
  4. Vitamin B6 Fact Sheet for Consumers:
  5. B-vitamins and exercise: does exercise alter requirements?:
  6. Vitamin B12 - Consumer:
  7. Zinc Fact Sheet for Consumers:
  8. Plasma/Serum Zinc Status During Aerobic Exercise Recovery: A Systematic Review and Meta-Analysis:
  9. The effect of exhaustion exercise on thyroid hormones and testosterone levels of elite athletes receiving oral zinc:
  10. Zinc status and serum testosterone levels of healthy adults - PubMed:
  11. The effect of nitric-oxide-related supplements on human performance:
  12. Levels of l-arginine and l-citrulline in patients with erectile dysfunction of different etiology:
  13. Oral L-citrulline supplementation improves erection hardness in men with mild erectile dysfunction:
  14. The Effect of Citrulline Malate Supplementation on Muscle Fatigue Among Healthy Participants:
  15. Acute Effect of Citrulline Malate Supplementation on Upper-Body Resistance Exercise Performance in Recreationally Resistance-Trained Men:
  16. Acute Citrulline-Malate Supplementation and High-Intensity Cycling Performance:
  17. A small plant with big benefits: Fenugreek (Trigonella foenum-graecum Linn.) for disease prevention and health promotion:
  18. Testofen, a specialised Trigonella foenum-graecum seed extract reduces age-related symptoms of androgen decrease, increases testosterone levels and improves sexual function in healthy aging males in a double-blind randomised clinical study:
  19. Physiological aspects of male libido enhanced by standardized Trigonella foenum-graecum extract and mineral formulation:
  20. The effects of a commercially available botanical supplement on strength, body composition, power output, and hormonal profiles in resistance-trained males:
  21. Tribulus terrestris versus placebo in the treatment of erectile dysfunction: A prospective, randomized, double blind study:
  22. Pro-sexual and androgen enhancing effects of Tribulus terrestris L.: Fact or Fiction:
  23. Insights into Supplements with Tribulus Terrestris used by Athletes:
  24. Mayo Clinic: Vitamin B-12:
  25. Harvard Health Publishing: Testosterone — What It Does And Doesn't Do:
  26. Increased physical activity has a greater effect than reduced energy intake on lifestyle modification-induced increases in testosterone:
  27. Testosterone concentrations in young pubertal and post-pubertal obese males:
  28. Natural bodybuilding competition preparation and recovery: a 12-month case study: