Finding a solution to the problem can be challenging when you struggle with low testosterone. Are you low in nutrients? Is it genetic? Is it age-related? There are many questions to ask yourself.

Regardless of the origin, low testosterone can be problematic - not just for your sex drive and manhood, but also for things like muscle mass, body fat, mood, and more.

Whether dealing with low levels or looking for a boost to maximize muscle growth, there are plenty of ways to naturally boost testosterone levels - one being arginine.

As a potent vasodilator and nitric oxide booster, there’s a fair bit of talk about the effect of the amino acid on T. How just how effective is it?

We’re digging through the research on the link between arginine and testosterone. We’ll cover what arginine is, how it works, influences testosterone, and the best natural alternative to boost testosterone levels.

Let’s get started.

What Is L-arginine?

L-arginine is classified as a conditionally essential amino acid; these amino acids are normally produced in the body from essential amino acids but become essential under certain conditions, such as pregnancy, infancy, serious illness, and trauma 1.

Although arginine plays several critical roles in the body, its most notable function is in the production of nitric oxide, a signaling molecule that’s involved in everything from regulating blood flow to mitochondrial function 2, 3.

On top of NO production, arginine also plays a role in developing T-cells, types of white blood cells involved in various immune responses. Because of its diverse roles in the body, arginine deficiency can impair cellular function and lead to serious adverse outcomes.

Some of the recognized benefits of L-arginine include:

  • Athletic performance enhancement
  • Blood pressure regulation
  • Critical illness management
  • Blood sugar regulation
  • Erectile dysfunction treatment
  • Blood flow improvement
  • Preeclampsia prevention and treatment

For most people consuming animal protein, getting enough arginine isn’t a problem - it’s widely available in protein-rich foods like meat, dairy, poultry, fish, nuts, and soy products - but can be a bit more challenging for those on a plant-based diet.

How Does L-arginine Work?

Many of the purported benefits of arginine are due to its role as a precursor to the signaling molecule nitric oxide and its ability to mediate endothelial function.

Nitric oxide is produced by enzymes called nitric oxide synthases, which convert arginine into another amino acid, L-citrulline, which produces NO as a by-product 4.

What Does Testosterone Do For The Body?

Testosterone is the male hormone most notably associated with manhood; it’s what gives men their characteristic “manly” features like a deep voice, facial and body hair, muscle mass, and of course, their sex drive.

But while testosterone might be thought of primarily as a male hormone, females have it also, albeit in much smaller quantities.

But for men, testosterone is more than just sex drive and muscle. It’s a sex and steroid hormone produced in the Leydig cells of the testes, with small amounts produced in the adrenal glands.

Although many men like to claim they have raging testosterone, production is actually under tight regulation by your hypothalamic-pituitary-gonadal (HPG) axis.

Hypothalamic stimulation leads to the release of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which in turn, stimulates Leydig cells of the testes to produce testosterone 5.

Although testosterone is essential for libido, it’s also involved in 6, 7:

  • Bone mineral density
  • Strength
  • Muscle mass
  • Insulin sensitivity
  • Mood
  • Body fat distribution
  • Red blood cell production
  • Sexual and physical health

For most men, testosterone levels remain high for most of their life, despite a natural decline after the age of 40.

Testosterone levels peak in the late teens and typically remain steady until about 40 when they start to decline at a rate of about 1% per year due to increases in sex-hormone binding globulin (SHBG) 8.

Even still, declining testosterone levels don’t happen as declining estrogen does for women - it’s a gradual decline over several decades, not a complete halt as it does in menopause.

So, if you’re concerned about your T levels tanking, don’t be. You won’t notice as drastic changes.

However, chronically low testosterone can eventually result in some pretty unwelcome symptoms, including:

  • Poor sex drive
  • Erectile dysfunction
  • Increase body fat
  • Weight gain
  • Loss of muscle mass
  • Low bone mineral density
  • Loss of body hair
  • Fatigue
  • Mood changes
  • Memory issues
  • Difficulty concentrating

Several factors can lead to low testosterone levels, with age being the most significant for men.

However, certain health conditions (obesity, genetic disorders, etc.), concurrent illness, medications, and excessive alcohol or drug use can also interfere with testosterone production and levels.

For situations like these, treating the root cause is recommended, but natural supplements to boost testosterone in the meantime could be beneficial.

The Link Between L-arginine And Testosterone

Of the available testosterone-boosting supplements, arginine gets a fair bit of attention.

Because your body naturally produces L-arginine, giving way to nitric oxide production, it’s been touted as a beneficial treatment for erectile dysfunction - and some animal research also suggests it can help boost testosterone levels 9, 10.

Its effects on humans aren’t apparent. Still, some research suggests it may benefit testosterone indirectly levels through its ability to stimulate the release of human growth hormone (HGH) and IGF-1 (a key growth factor), both of which are integral to muscle growth 11.

Supplementing with arginine can support muscle growth, promote growth hormone release, and encourage greater fat metabolism. However, little evidence suggests it has a direct and indirect effect on increasing testosterone levels.

Best Supplements For Naturally Increasing Testosterone

With that said, if you’re struggling with low testosterone or want to increase your levels for performance, there are some fantastic supplements to try instead with proven efficacy.


You’ve probably heard about ashwagandha before concerning stress.

The traditional herbal medicine used for centuries does more than just calm the nervous system and reinstate balance within the body, however. Studies show that it can work wonders for male fertility and reproductive function.

A 2010 study looked at the effects of ashwagandha supplementation on infertile men and found improvements in oxidative stress levels, testosterone levels, sperm count, sperm motility, and semen antioxidant levels 12.

Another study found significant increases in DHEA and testosterone but little effect for those taking a placebo 13.

The primary reason it’s so effective for testosterone levels and male sexual health is its ability to mitigate stress. Chronic stress causes cortisol levels to rise, and several studies show a link between cortisol and testosterone.

They have an inverse relationship - chronically high cortisol interferes with testosterone levels; as one increases, the other decreases. Elevated glucocorticoids (including cortisol) exert an inhibitory effect on testicular Leydig cell function, leading to lowered testosterone production 14.

Studies find that it disrupts testicular testosterone production of testosterone by interrupting the hormone’s biosynthesis pathway.

Because ashwagandha can increase the body’s response to stress and enhance resiliency, it can attenuate the adverse effects of stress on body function and hormone production.

But there’s more - for centuries, ashwagandha has also been touted to promote youthful vigor, enhance muscle strength and endurance, and improve overall health 13.

That said, it’s not just any ashwagandha - it’s KSM-66, the most potent Ashwagandha supplement on the market and the only choice to boost testosterone in Testo Lab Pro®.

It’s a full-spectrum, 100% certified organic ashwagandha extract standardized to 5% active withanolides that have been extensively studied for various masculine vitality benefits.


Where men’s health is concerned, zinc is essential. It’s a micronutrient needed for immune health, DNA production, wound healing, sperm function, and more.

While the exact link isn’t clear, studies indicate that zinc and testosterone could be connected.

A good amount of research supports the role of zinc supplementation for hypogonadal men, showing that just 30mg daily could boost free testosterone levels 15.

Similarly, another study shows an obvious link between zinc and testosterone levels, finding that zinc-devoid diets were a trigger for low testosterone; after 20 weeks on a low-zinc diet, testosterone levels plummeted by a whopping 75% 16. However, the how isn’t clear.

Macuna pruriens extract

Never heard of Macuna pruriens extract before? Don’t sweat it; you’re not alone.

It’s a new herbal supplement on the scene and an awesome one for supporting male health. Sometimes called velvet mean, this herb is prized in Eastern herbalism for its effects on male vigor, virility, and sex drive.

That’s because the primary constituent of Macuna pruriens, levodopa (L-DOPA), and its metabolites are potent compounds for boosting brain concentrations of dopamine.

Dopamine is known as the pleasure and reward neurotransmitter, but it also stimulates male sex drive.

Research finds that supplementing with it can have beneficial effects on testosterone, LH, dopamine, adrenaline, and noradrenaline levels in infertile men 17.

It’s said that boosting dopamine levels could optimize the release of testosterone but may also reduce psychological stress 18 - both critical for maintaining proper levels.

D-Aspartic acid

D-aspartic acid (DAA) is an amino acid naturally present in the central nervous system and reproductive tissues.

While amino acids are generally used to build proteins, DAA is preferentially put towards hormone synthesis, making it an excellent option for boosting testosterone.

How? DAA influences HPG (hypothalamic-pituitary-gonadal) axis function at three levels: hypothalamus, anterior pituitary, and testes.

Levels of d-aspartic acid accumulate in these tissues, which upregulates testosterone production and upstream effectors of the HPG axis like luteinizing hormone 19.

Other research points to DAA’s effects on increasing the release of gonadotropin-releasing hormone (GnRH), and acting on the pituitary gland to secrete prolactin (PRL), luteinizing hormone (LH), and growth hormone (GH), and in the testes, stimulates Leydig cells to release testosterone and progesterone20.


One of the big reasons men see age-related decreases in testosterone is from an enzyme called aromatase; levels increase as men get older, increasing the conversion of testosterone to estrogen.

However, luteolin, a powerful botanical derived from oranges, can potentially mitigate age-related testosterone issues by blocking the aromatase enzymes, halting its conversion to estrogen. It may also increase steroidogenesis by upregulating StAR expression 22.

Final Thoughts

Dealing with low testosterone can be stressful, but while arginine may not be the best bet for increasing levels, plenty of other natural supplements can do the job.

Whether it’s vitamin D, zinc, luteolin, or a combination of them in something like Testo Lab Pro, they’re solid, research-backed options for boosting hormones and regaining your manhood.


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