Saw palmetto is a plant extract derived from the berries of the Serenoa repens tree. It's often marketed as a natural alternative to hair loss treatments because of its potential to reduce levels of DHT, the primary hormone responsible for male pattern baldness.
But how effective is it really?
In this article, we'll explain what DHT is, how saw palmetto is thought to work, and what the research says about how well saw palmetto works as a hair loss remedy.
What is DHT?
DHT, which stands for dihydrotestosterone, is a by-product of testosterone which is the primary driver of androgenetic alopecia (male pattern baldness).
Even though all men (and women for that matter) produce DHT, it doesn’t affect everybody in the same way. Some are genetically more sensitive to the hormone, which binds to hair follicles and triggers a process called miniaturisation.
Hair follicles start to shrink, the growth phase of the hair growth cycle gets shorter, and the follicle produces shorter, weaker hairs over time.
That’s why lots of hair loss treatments aim to prevent or stop hair loss by reducing DHT levels to limit the damage to hair follicles. They often do this by inhibiting the enzyme, 5α-reductase, that is responsible for converting testosterone into DHT.
Saw Palmetto
Saw Palmetto is thought to have anti-androgenic properties, meaning it may help counteract the impact of DHT. In a human cell culture, researchers found that saw palmetto inhibited 5α-reductase, so less DHT was produced within these cells. Plus, they also found that saw palmetto competitively binded to androgen receptors, which reduced DHT binding to receptors by 50%.
So the properties of the plant have been demonstrated, but how does this actually translate into its use as a treatment for hair loss in humans?
In a clinical trial, participants with male pattern baldness took either 1mg of finasteride or an oral supplement containing 320mg saw palmetto. After 2 years of treatment, 68% of those using finasteride saw an increase in hair growth compared to 38% of saw palmetto users. While finasteride was effective on both the vertex (crown) and front of the scalp, saw palmetto worked mostly in the vertex area. According to this study, saw palmetto can lead to an improvement in androgenetic alopecia, but proved less effective than finasteride.
A 2020 systematic review considered 9 articles using saw palmetto as a treatment for male pattern baldness, involving 381 patients. The problem is the concentrations and format of saw palmetto was different in all the studies – some used topical versions, some oral. The concentrations were different across the studies, and often saw palmetto was just one ingredient within a combination supplement or serum containing other active ingredients, so it’s hard to draw firm conclusions on the efficacy of saw palmetto by itself.
Is topical or oral saw palmetto better?
Saw Palmetto can be taken as either an oral supplement or applied directly to the scalp as a topical formulation. But which works better?
One study looked into exactly this. 80 male and female participants were divided into four groups, either receiving 400mg of a supplement containing saw palmetto oil, a topical formulation containing 20% saw palmetto oil, or the respective placebo. After 16 weeks, the oral supplement reduced hair shedding by 29% and the topical formulation by 22.19%. Hair density increased by 5.17% and 7.61% respectively. The study also found that oral saw palmetto significantly reduced serum DHT levels (meaning the DHT levels in the blood) compared with placebo.
So, it would appear from the results of this study that oral saw palmetto might have the edge over topical. However, the evidence is far less extensive compared to the robust body of evidence supporting licensed treatments such as Finasteride and Minoxidil Spray, for either version.
Should you use saw palmetto or finasteride?
For some people, the appeal of saw palmetto lies in the fact that it is a natural product.
They might be looking for a hair loss treatment which blocks DHT, in which case the first line recommendation is typically finasteride if suitable, but are put off by the idea of taking medication or by the potential risk of side effects.
While saw palmetto may be capable of suppressing DHT and may help reduce hair shedding, the evidence consistently shows that finasteride has a greater effect. Furthermore, finasteride has a much more extensive body of clinical evidence and real-world data to support it as a safe and effective hair loss treatment.
With this in mind, saw palmetto is best used as a complement to proven treatments, rather than the main defence against male pattern baldness.
[RJ1] could link to article here: https://sons.co.uk/blogs/journal/dht-101-sons-explainDHT 101: Sons Explain – Sons UK
All of our blog articles are reviewed by our Medical Director before publication.
