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Does Saw Palmetto Increase Testosterone? (From A Dietitian)

Connor Sellers
Published by Connor Sellers | Senior Coach
Last updated: August 9, 2023
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If you have spent as much time as I have in the gym as a fitness trainer, you’ve probably heard it all when trying to increase testosterone. Saw palmetto still comes up in conversations as a great way to boost T levels.

To build upon my existing knowledge, I spent hours on the internet examining research, and I sat down with our dietician to have a candid discussion about this curious fruit and its link to testosterone levels.

Let’s take a look.

Quick Summary

  • Saw Palmetto can be used to boost testosterone levels, for individuals who want to do it naturally.
  • Some health benefits of using Saw Palmetto include; boosting prostate health, increasing hair growth rate, and preventing inflammation.
  • It can take between 4 to 6 weeks for an individual to see the benefits of Saw Palmetto.

Does Saw Palmetto Increase Testosterone?

A buff male holding a bottle of Saw Palmetto pills

Saw palmetto can increase testosterone in people looking to boost testosterone levels naturally, and several studies support this assertion.

Before we dive into research and the link between saw palmetto and testosterone levels, let’s look at what saw palmetto, also known as Serenoa repens, is.

Since low testosterone can affect both men’s and women’s libido, the target market for saw palmetto is not limited to men.

What is Saw Palmetto?

Saw palmetto (Serenoa repens) is a type of palm tree that produces fruit used for medicinal purposes.

Saw palmetto is native to the southeastern United States and can grow up to ten feet tall.

It is available as whole berries, powder, and liquid. Saw palmetto extract capsules are the most common dietary supplement form.

Additionally, topical saw palmetto has gained traction as a treatment for hair loss.

You should make sure to purchase from reputable sources and get a standardized product that contains 85% to 95% fatty acids and sterols.

How Does Saw Palmetto Work?

A person holding a saw palmetto pill

Saw palmetto may work by blocking 5-alpha reductase, the enzyme that converts testosterone into Dihydrotestosterone (DHT). DHT is another androgen involved in muscle mass, hair growth or loss, and prostate health [1].

Saw palmetto also inhibits the binding of DHT to an androgen receptor, further helping regulate testosterone levels and, perhaps, counteracting hair loss [2].

The benefits seem to be more widely accepted in Europe and Asia, while the medical community in the United States remains more skeptical.

Now let’s look specifically at how saw palmetto may regulate testosterone levels.


There are mixed opinions on whether using palmetto extracts effectively increases testosterone levels.

One open-label, dose-response study found that healthy males taking a saw palmetto dietary supplement had increased testosterone levels after two weeks [3].

Another 14-day study shows that males who took Resettin®, a dietary supplement of saw palmetto and astaxanthin, saw a 38% increase in serum hormone levels [4].

One systematic review urges caution and encourages further research on the efficacy of saw palmetto on DHT levels resulting in better regulation of testosterone levels [5].

“Test-tube, human, and animal studies show that saw palmetto could help regulate testosterone levels by decreasing the activity of an enzyme that converts testosterone to DHT.”

- Rachel Link MS, RD


A couple happy in bed smiling at each other

Low testosterone can decrease sex drive, and many believe that because saw palmetto reduces the breakdown of testosterone into DHT, it allows the libido to increase. Many clinical trials examine how this supplement can boost libido in both men and women.

Let’s take a look at one well-cited study.

Researchers followed 120 patients with benign prostatic hyperplasia (BPH) or enlarged prostate over two years to study the effect of saw palmetto on sexual function and prostate symptoms [6].

They monitored:

  • Urine flow
  • Blood prostate-specific antigen
  • Prostate symptoms
  • Erectile function
  • Quality of life

The study showed significantly improved sexual function and BPH symptoms after the first year.

Other Benefits

A doctor holding a green pill with confusion

Besides the perceived benefits of regulating testosterone and libido, there are a few other potential benefits of saw palmetto worth mentioning.

1. Prostate Health

The prostate is a small walnut-sized gland that sits just below the bladder, and it helps produce and transport semen, making it a vital part of male reproductive health.

Benign Prostatic Hyperplasia

Saw palmetto may be beneficial in treating benign prostatic hyperplasia (BPH) and prostate enlargement, as shown by a 2014 randomized controlled trial that found this particularly true when combined with other natural therapies [7].

Prostate Cancer

Studies show that saw palmetto might inhibit the growth of prostate cancer cells [8].

Another study, looking at the effects of the extract of saw palmetto berries, further supports its ability to inhibit the growth of prostate cancer cells [9].

One study found that saw palmetto could be an effective treatment for individuals with prostate cancer, showing the potential to slow the growth. [10].

“Evidence related to saw palmetto’s ability to improve prostate health and urinary function is mixed. Some studies report that it may improve urine flow and reduce nighttime urination, but others find no effect. More research is needed.”

- Alina Petre, MS, RD

2. Hair Growth

A man with a receding hairline

Male androgenetic alopecia, also known as male pattern baldness, is the most common form of hair loss for men, and it affects 30-50% of men by age 50 [11].

Too much DHT can be the culprit in hair loss as it can shrink the hair follicles and cause hair to grow thinner or more brittle [12].

This action is why saw palmetto’s hormone-regulatory effect of blocking DHT, as discussed earlier, can play a beneficial role in hair loss.

One study of 50 male volunteers, ages 20 and 50, shows that a topical application of saw palmetto extract effectively promotes hair growth [13].

Another study in mice showed that saw palmetto promotes the regeneration of hair, as well as the repair of hair loss by activating TGF-β and mitochondrial signaling pathways [14].

3. Inflammation

There are minimal human studies, but animal studies show promise when evaluating the efficacy of saw palmetto in decreasing inflammation.

A study in rats with enlarged prostates showed that saw palmetto oil reduced swelling and several other indicators of inflammation [15].

4. Female Health

A female doctor and patient discussing with each other

While the focus here has been on the male reproductive system, low testosterone levels, prostate, and male pattern hair loss, saw palmetto may also have its place as a supplement for women, as it may have an opposite effect on testosterone for them.

Women with polycystic ovary syndrome (PCOS) have high levels of testosterone, which can cause side effects, including irregular or heavy menstrual cycles, excessive body or facial hair, and acne [16].

Studies continue to focus on saw palmetto and other plant-based anti-androgens to evaluate their effectiveness in reducing PCOS symptoms [17].

However, more research needs to be done to fully understand the mechanisms involved.

Side Effects

Taking medications and natural supplements has a risk of side effects and saw palmetto is no different. Most users report that any side effects they experience are mild [18].

They include:

  • Dizziness
  • Headache
  • Diarrhea
  • Nausea
  • Stomach pain
  • Bad breath
  • Constipation

Interactions With Medications

A doctor pointing to a notebook

If you consider supplementing with saw palmetto, you should know of a few drug interactions [19].

Saw palmetto can interact with:

  • Finasteride (Proscar) or other medications treating benign prostatic hyperplasia.
  • Antiplatelet and anticoagulant drugs (blood-thinners), like Warfarin (Coumadin), Clopidogrel (Plavix), and Aspirin.
  • Oral contraceptives and hormone replacement therapy may decrease the efficacy of oral contraceptives and increase the risk of unplanned pregnancy.


How Quickly Does Saw Palmetto Work?

Saw palmetto may work as quickly as four to six weeks when taking 320 mg daily; though there is no recommended dose, 320 mg daily is standard [19].

What Is the Best Time to Take Saw Palmetto?

The best time to take saw palmetto is with a meal, which can minimize digestive upset or other adverse side effects.

Can Saw Palmetto Help With Erectile Problems?

Saw palmetto can help erectile problems by acting as a phosphodiesterase 5 (an enzyme) inhibitor, promoting vasodilation and increasing blood and oxygen flow [20].

Final Thoughts on Saw Palmetto and Testosterone

Saw palmetto research shows promise for prostate problems, hormone regulation, and hair growth.

However, we cannot overlook the mixed study results and medical community skepticism. Further research is certainly warranted.

I offer an alternative solution worth considering for anyone experiencing the plethora of adverse effects that accompany low testosterone.

After extensive testing, we compiled lists of testosterone boosters with proven formulas to boost levels, combat fatigue, and improve body composition.

Click the link to find the best products to recoup your testosterone levels.


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