If you've spent any time in menopause forums or hair loss communities, you'll have seen saw palmetto mentioned again and again. "My shedding slowed within two weeks." "My scalp is nowhere near as oily." "Why did nobody tell me about this sooner?"
Anecdotes are encouraging, and they're also just anecdotes. You deserve to know what the research actually says, including where it's thinner than the enthusiasm suggests. Here it is, without the hype.
What saw palmetto is
Saw palmetto (Serenoa repens) is a small palm native to the southeastern United States. Its dark berries contain fatty acids and plant sterols that have been studied for decades, originally for prostate health in men, where the research base is genuinely substantial. The hair application came later, and for a logical reason: both conditions involve the same hormone.
How it's thought to work
Saw palmetto appears to inhibit 5-alpha reductase, the enzyme that converts testosterone into DHT. DHT is the hormone that shrinks sensitive scalp follicles through the process of miniaturisation, and it becomes relatively more influential in women after menopause as oestrogen, its natural counterweight, declines.
Research shows saw palmetto can help reduce DHT levels by up to 30%. Less DHT reaching a sensitive follicle means less pressure on that follicle to shrink with each cycle. It's the same mechanism the prescription drug finasteride uses, at considerably gentler strength, which is both its main advantage and its main limitation.
What the studies show
Being straight with you about the evidence base:
-
A 2020 review of saw palmetto research in hair loss, covering several hundred participants across multiple studies, reported improvements in hair density or quality in the majority of studies reviewed, alongside a favourable tolerability profile.
-
Studies have typically used oral doses of around 200 to 320mg daily, assessing outcomes across three to six months. The timeframe is not optional: hair cycles are slow, and studies shorter than a few months tell you very little.
-
A two-year comparative study in men with mild-to-moderate pattern loss found improvement in around 38% of the saw palmetto group versus around 68% on finasteride. Read honestly: finasteride is the stronger agent, and saw palmetto still produced improvement in roughly four in ten men, with better tolerability.
-
Most importantly for women: because saw palmetto is a gentler modulator rather than a potent pharmaceutical blocker, it has been studied in mixed and female populations. Finasteride is licensed for men only in the UK, which leaves women with far fewer prescription DHT options and makes the natural route more relevant, not less.
The honest caveat: the female-specific evidence base is smaller than the male one, because research funding in hair loss has historically followed men. That's frustrating and it's true, and I'd rather tell you than pretend otherwise. The mechanism applies to female follicles the same way it applies to male ones, and the studies that have included women support that, but anyone claiming vast female-specific trial data is overstating it.
What women report noticing first
Two things come up consistently, and both make mechanistic sense.
Reduced scalp oiliness. Often within the first week or two. DHT stimulates sebum production, so as DHT influence reduces, oiliness frequently settles first. Women describe waking up without the greasy scalp they'd resigned themselves to. It isn't hair growth, but it's a very early sign the mechanism is responding.
Slower shedding. Usually within the first few weeks. Fewer hairs in the brush and the plughole. Again, this is the absence of loss rather than the presence of growth, and it's the correct first milestone.
New growth takes considerably longer. Follicles need a full cycle to respond, so think months, not weeks. Around month three for the first fine baby hairs, building visibly from month six.
Dose and pairing matter more than brand
This is where most supplements fall down. A "hair complex" with 25 ingredients sounds impressive and usually contains a dusting of each: enough to print on the label, nowhere near enough to match what any study used.
Our Hair Growth Softgels contain 300mg of saw palmetto, within the range used in research, paired with 400mg of pumpkin seed oil: the exact dose from the 2014 study (Cho et al.) that found a 40% increase in mean hair count over 24 weeks. Two ingredients, both with real human evidence, both at research-matched amounts, and nothing padding out the label.
We paired them deliberately. They work on the same DHT pathway from slightly different angles, and combining them in one softgel means you're not juggling two bottles and two schedules, which is the fastest route to giving up by week six.
Sensible cautions
Saw palmetto acts on hormones. That's exactly why it's worth taking and exactly why it deserves respect.
-
Do not take it if you are pregnant or breastfeeding.
-
Speak to your GP first if you're on HRT, hormonal medication such as spironolactone, or blood thinners.
-
Occasional mild digestive upset is the most commonly reported effect in studies. Taking it with food helps.
-
It supports your hair. It doesn't replace medical treatment where that's genuinely needed, and if your GP or dermatologist recommends a licensed treatment, that recommendation deserves proper consideration rather than dismissal.
The realistic verdict
Saw palmetto is not a miracle and anyone selling it as one is selling you something. What it is: the best-evidenced natural option for reducing the hormone that drives menopausal thinning, with a good tolerability record, available without a prescription in a category where women have very few prescription options anyway.
For early to moderate hormonal thinning, taken at a proper dose, consistently, for long enough to matter, it's a rational and well-supported place to start. The forums aren't wrong. They're just, as ever, missing the bit about dose and patience.