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Saw Palmetto and Hair Loss
Dr. Michael May (FRCS)
Medically reviewed by
Dr. Michael May (FRCS)
Updated on March 29, 2024

If you are suffering from hair loss, you will no doubt have done considerable research for remedies and treatments to try and fix or cure your hair loss, whatever the cause. Whilst many people opt for disguising their hair loss with hats, hairpieces, wigs and extensions, others look to oral or topical medications and eventually hair transplants.

Given that many medications have side effects as well as the fact that many people see hair transplants as a last resort or believe hair transplant costs are too high, we often find people look to alternative remedies for their hair loss, including the use of herbal remedies such as saw palmetto to treat their thinning hair.

Table of Contents

What is saw palmetto?

Saw palmetto is a shrub-like type of palm tree that is native to the southeastern United States. Its Latin name is Serenoa repens, Serenoa serrulata or Sabal serrulata. It can also be called the American dwarf palm tree or cabbage palm. It produces small fruits or berries and it is these berries from which saw palmetto supplements are extracted.

Historically, Native Americans used the saw palmetto tree for centuries to treat a variety of ailments including male and female reproductive disorders as well as coughs[1]. 

Today, it is commonly used as a dietary supplement. Many men use it for urinary symptoms caused by benign prostatic hyperplasia (BHP), commonly known as an enlarged prostate and indeed, some studies show its efficacy in this regard [2]. It is also used for chronic pelvic pain, migraines and hair loss among other conditions. 

bottle of saw palmetto extract

The relationship between saw palmetto and hair loss

There are many different types of hair loss. One of the more common forms of hair loss is androgenetic alopecia (a genetic hair loss condition known as female pattern hair loss in individuals assigned as female at birth or male pattern baldness in individuals who have been assigned as male at birth).In men, androgenetic alopecia is characterised by a gradual hair thinning and/or loss of hair in a typical ‘M’ shaped pattern.

This type of hair loss is largely caused by genetic factors that influence the hair follicles and their response and reactivity to the male sex hormone dihydrotestosterone (DHT). Testosterone is converted to DHT in small amounts thanks to an enzyme known as 5-alpha reductase. DHT levels are normally around 10% of the overall testosterone levels [3]. 

DHT is very potent and can have noticeable effects on your hair. It can bind to receptors in the scalp which causes them to shrink and prevents the hair follicles from producing new hairs [4]. This then causes a receding hairline, balding areas and eventually male pattern baldness. High levels of DHT are also associated with prostate enlargement [5].

miniaturisation leading to hair loss informational graphic

So, what does this all have to do with saw palmetto? 

Saw palmetto is said to interact with 5-alpha reductase, reducing its ability to convert testosterone into DHT. With less DHT in the body, the effects of it on the hair follicles are reduced, meaning reduced hair loss.

In a study comparing its effectiveness with that of the DHT-blocking medication Finasteride, only 38% of patients treated with saw palmetto had an increase in hair regrowth, while 68% of those treated with Finasteride noted an improvement. Find out more about saw palmetto vs Finasteride for hair loss.

The science behind saw palmetto and hair loss

The fruit from saw palmetto and its extract contain many compounds including biologically active monoacylglycerides with cytotoxic activity on human prostate cells [7]. This is just one of the mechanisms in which saw palmetto extract works on its target tissue, including prostate and hair follicles.

The extract also contains:

  • Triglycerides
  • Phytosterols (beta-sitosterol, stigminerol, campesterol, cycloartenol)
  • Fatty acids (capric, caproic and caprylic, lauric, myristic, oleic and palmitic), and their derivatives
  • Various flavonoids (kaempferol, quercetin, isoquercitrin, roifolin, farnesol, lupeol, etc.).

The inhibitors of 5-alpha reductase are more likely to come from the group of phytosterols. Due to this useful composition, saw palmetto has been used as a remedy for ailments associated with the urinary tract in men as well as other conditions.

Saw palmetto and its effect on androgenetic alopecia

When Serenoa repens is used in therapy for androgenetic alopecia, it acts like a competitive, non-selective inhibitor of 5-alpha reductase [8] which is the enzyme responsible for converting testosterone to DHT – the hormone responsible for hair loss. DHT is also responsible for the growth of the prostate which causes urinary problems in men, so this explains why using the extract can also have an impact on the role DHT plays in androgenetic alopecia.

To explain this more simply, saw palmetto inhibits the conversion of testosterone to the hair-loss-associated hormone DHT. In effect, it reduces its effect on hair follicles [9]. As such, it can reduce hair loss, working as a potential therapeutic for those suffering from conditions such as androgenetic alopecia. 

According to one study, Serenoa repens is a “non-invasive” approach to androgenetic hair loss with no side effects [10], which explains why it is a popular choice for those wanting a natural and simple solution to hair loss. However, its efficacy is not particularly high compared with other treatments for hair loss.

Based on a survey by the International Society of Hair Restoration (ISHRS), members reported prescribing Saw palmetto often (9.1%), sometimes (11.4%), and rarely/never (79.4%). It ranked last among medications, with Finasteride and Minoxidil taking the top two spots respectively.

Chart showing the medications prescribed to treat hair loss and promote hair growth by ISHRS members

A review of the existing literature on saw palmetto and hair loss

There is not a lot of research available on the efficacy of saw palmetto when it comes to reducing or preventing hair loss. However, it can certainly be said that the botanical extract has gained popularity in recent years. So, what do existing studies show?

A study in 1998 revealed that long-term treatment with Serenoa repens showed a significant decrease in DHT in men with benign prostatic hyperplasia (BHP), confirming its capacity to inhibit 5-alpha reductase [11]. It states that these biochemical effects are similar to those obtained with Finasteride – a drug that’s also used in reducing hair loss in men.

In essence, it is a natural product that can replicate the synthetic ingredients in Finasteride or similar prescription medications to some limited extent. However, the effects of saw palmetto are significantly smaller than the effects achieved with Finasteride [6].

Later, a 2016 study also showed that saw palmetto inhibits the activity of the enzyme linked to BHP (and therefore male androgenetic alopecia hair loss) and that the amount of the extract that is required is comparatively low [12]. Whilst this showed its effectiveness on prostate health, a 2018 study also showed its efficacy where Serenoa repens extract promoted hair regeneration and repair of hair loss in mice [13]. 

A systematic review of saw palmetto (Natural Hair Supplement: Friend or Foe? Saw Palmetto, a Systematic Review in Alopecia) [14] published in 2020 showed that the extract improved the overall hair quality by 60%. There was also a 27% improvement in the total number of hairs and an increased density in over 83% of patients. What’s more, hair loss was stabilised in 52% of patients.

This review also showed that saw palmetto was tolerated well by patients without any significant adverse effects and summarised that it may be a viable treatment option for those with telogen effluvium, self-perceived hair thinning and indeed AGA.

Whilst research is not overly plentiful, studies so far show that saw palmetto (Serenoa repens) certainly has a lot of promise as a hair loss remedy.  However, when looking at its efficacy, other research does not seem to back up its effects. Two large studies using different saw palmetto preparations found that it was no more effective than a placebo when treating symptoms of BHP [15].

Whilst these studies weren’t testing the effects on hair loss specifically, they do call into question saw palmetto’s efficacy where reducing DHT activity is concerned. 

Different forms of saw palmetto available

Saw palmetto comes in different forms, including tablets, powder capsules, liquid extracts and even whole dried berries. The easiest forms to find are tablets and capsules, with many herbal retailers in the UK stocking these.

Making tea from dried berries is not likely to be successful as the active components in the berries are not water-soluble. However, before taking any new supplement, it’s wise to consult your doctor.

supplements spilling out of a bottle

Dosage and potential side effects of saw palmetto

When taking saw palmetto for an enlarged prostate, it is taken in quantities of 320mg per day. As such, this is generally considered the appropriate dose if taking the extract to treat hair loss. Tablets and capsules that are commonly found over the counter in UK herbal stores often have this dosage.

In terms of side effects, some people have reported mild headaches or stomach aches but this is rare. Taking saw palmetto with food can help reduce any irritability in the stomach. Some individuals have reported an increase in breast tissue in men, but this is extremely rare and there is no significant research or evidence to back up this claim.

It’s not recommended to take saw palmetto if you take any other drugs used to treat androgenetic hair loss or an enlarged prostate such as Finasteride. It also should not be taken with drugs that thin the blood such as Aspirin or Warfarin.

Saw palmetto is generally considered safe, though like most remedies it’s not recommended for children and pregnant or breastfeeding women. A 15-year study published in 2018 proved Saw Palmetto to be effective and safe in treating men with BPH [16]. As such, similar conclusions can be drawn regarding its safety when taken as a supplement or medication to treat androgenetic alopecia.

What is more, it is not known to interact with the prostate blood screening test (PSA) for men, unlike other medications such as Finasteride. However, before taking any new supplement, it’s sensible to consult your doctor. 

How to use saw palmetto for hair loss

Unfortunately, simply eating the berries of the saw palmetto plant will not work. To use saw palmetto in adequate concentrations for an effect you need the extract, which is why taking capsules or tablets is the most effective way of using saw palmetto.

To use saw palmetto for hair loss you should first consult your doctor. As with taking any supplement, only your doctor can reassure you that it is safe for you to take based on your health and circumstances.

Many recommend taking saw palmetto tablets or capsules with food to avoid any potential irritation on your stomach. Normally, one or two capsules are taken per day, depending on the potency.

Can women use saw palmetto?

Research into saw palmetto use among women is even less than it is among men. The effect of it on female sex hormones is not well understood and, as such, it is recommended that pregnant and/or breastfeeding women do not take saw palmetto.

Whilst the research is not yet conclusive, many believe that as saw palmetto can work as a potential anti-androgen, it could help balance the hormones in women who suffer from polycystic ovary syndrome (PCOS) and help reduce the symptoms such as excess body hair growth or female facial hair. Its effects on female pattern hair loss are even less well understood. Read more about the safety and efficiency of saw palmetto for women with hair loss.

Woman with minimal hair growth

Does saw palmetto work for all types of hair loss?

Whether saw palmetto works as a hair loss treatment is still up for debate. Given that there are many different types of alopecia (the catch-all term for all types of hair loss), it will not work for all types. For example, alopecia areatafrontal fibrosing alopecia and lichen planopilaris all have an autoimmune cause. Other types of hair loss are caused by hair styling such as central centrifugal cicatricial alopecia and traction alopecia. Chemotherapy-induced hair loss will also be unresponsive to saw palmetto (and likely isn’t recommended alongside cancer treatment).

If saw palmetto is to have any effect on types of hair loss, it is most likely to affect hair loss that is caused by hormonal factors such as androgenetic alopecia. This is because the mechanism behind this type of hair loss is due to DHT, the form of testosterone that affects the hair follicles.

saw palmetto plant

Final thoughts on saw palmetto and hair loss

When it comes to saw palmetto and hair loss, the jury is still out and much more research is needed. That said, there are some positive findings and correlations in results between those who have used it and reduced hair loss.

Given that saw palmetto is an inexpensive alternative to many hair loss treatments and that it is very safe, it is certainly worth exploring for many men who are willing to give it a try to promote hair growth and reduce further hair loss.

Saw Palmetto and Hair Loss, Wimpole Clinic

  1. Saw Palmetto | NCCIH (
  2. Efficacy and Safety of Serenoa repens Extract Among Patients with Benign Prostatic Hyperplasia in China: A Multicenter, Randomized, Double-blind, Placebo-controlled Trial – PubMed (
  3. Biochemistry, Dihydrotestosterone | NCBI
  4. Causes of Androgenic Alopecia: Crux of the Matter
  5. Testosterone and DHEA activate the glucose metabolism-related signaling pathway in skeletal muscle – PubMed (
  6. Comparative Effectiveness and Finasteride Vs Serenoa Repens in Male Androgenetic Alopecia: A Two-Year Study – A. Rossi, E. Mari, M. Scarnò, V. Garelli, C. Maxia, E. Scali, A. Iorio, M. Carlesimo, 2012 (
  7. The Use of Serenoa Repens (Saw Palmetto) in Hair Care Products (
  8. Comparative Effectiveness and Finasteride Vs Serenoa Repens in Male Androgenetic Alopecia: A Two-Year Study (
  9. The Use of Serenoa Repens (Saw Palmetto) in Hair Care Products (
  10. Comparative Effectiveness and Finasteride Vs Serenoa Repens in Male Androgenetic Alopecia: A Two-Year Study (
  11. Effects of long-term treatment with Serenoa repens (Permixon) on the concentrations and regional distribution of androgens and epidermal growth factor in benign prostatic hyperplasia – PubMed (
  12. Determination of the potency of a novel saw palmetto supercritical CO2 extract (SPSE) for 5α-reductase isoform II inhibition using a cell-free in vitro test system – PMC (
  13. Serenoa repens extracts promote hair regeneration and repair of hair loss mouse models by activating TGF-β and mitochondrial signaling pathway – PubMed (
  14. Natural Hair Supplement: Friend or Foe? Saw Palmetto, a Systematic Review in Alopecia – PubMed (
  15. Saw Palmetto | NCCIH (
  16. 15 years’ survey of safety and efficacy of Serenoa repens extract in benign prostatic hyperplasia patients with risk of progression – Andrey Zinovievich Vinarov, Leonid Grigorievich Spivak, Darina Vladimirovna Platonova, Leonid Mikhailovich Rapoport, Dmitry Olegovich Korolev, 2019 (
Dr. Michael May (FRCS)
Medically reviewed by Dr. Michael May (FRCS)Updated on March 29, 2024
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