Anyone who compares the ingredient lists of hair serums will come across Capixyl more and more often. On Reddit, it appears mainly in lists: "Redensyl, Procapil, Capixyl." As if it were one single package. What Capixyl actually does, and how strong the evidence for it is, is rarely explained.
We do try to do that here. You will read what is in Capixyl, what it does to your scalp, what studies exist, and what they do and do not show. The question that frequently pops up on forums is also addressed: red clover contains plant estrogens; should you be concerned about that as a man?
What is Capixyl?
Capixyl is not a single substance but a brand name for a combination of two ingredients. It was developed by Lucas Meyer Cosmetics, a Canadian raw material supplier for the cosmetics industry.
- Acetyl tetrapeptide 3. A short protein chain of four amino acids, replicated in the lab. Such a peptide acts as a signal for cells in the skin.
- Red clover extract (Trifolium pratense). This extract is rich in biochanin A, a plant substance from the isoflavone group.
So, on an ingredient list, you usually won't see the word Capixyl, but "acetyl tetrapeptide 3" and "trifolium pratense flower extract."
What does Capixyl do to your scalp?
The two components each have their own task. That makes Capixyl different from an ingredient that only boosts blood circulation.
Red clover: a brake on DHT
In hereditary hair loss, the enzyme 5-alpha reductase converts testosterone into DHT. In men with sensitive hair follicles, DHT causes those follicles to shrink slowly. You can read exactly how that happens in DHT and hair loss.
Biochanin A inhibits that enzyme in lab research. This has been measured in test tubes and cell cultures, not in the scalps of men. No one has ever measured DHT in the scalps of Capixyl users. So don't compare it to finasteride, for which we know exactly how much it lowers DHT. It is more comparable to other plant-based DHT inhibitors such as saw palmetto: a logical mechanism, but its potency in humans is unknown.
The peptide: better hair anchorage
A hair follicle is fixed in a kind of scaffolding of proteins, such as collagen and laminin. With hair loss, that scaffolding around the follicle becomes weaker. According to lab research by the manufacturer, acetyl tetrapeptide 3 stimulates the cells around the hair root to produce more of those proteins. The idea: a hair that is anchored more firmly falls out less easily, and the follicle becomes larger.
In the same lab work, both substances also inhibited inflammatory substances. This is relevant because hereditary hair loss is often accompanied by slight, invisible inflammation around the hair follicle.
What do studies in humans show?
This is where it becomes important to read carefully. There are three studies that are often cited, and all three have different designs.
1. The manufacturer's study (2013)
Thirty men with hereditary hair loss used a lotion containing 5% Capixyl or a placebo for four months. Measurements were taken using a phototrichogram, a magnified photo of a small area of the scalp.
- 13% more hairs in the growth phase in the Capixyl group.
- 29% fewer hairs in the resting phase.
- The ratio of growing to resting hairs increased by 46%. In the placebo group, it actually decreased by 33%.
That sounds strong, and the design with a placebo group is good. But it is a small group, it lasted four months, and the researchers worked for the company that sells Capixyl. It was published in the Journal of Cosmetic Science, not a major medical journal.
2. The Thai study against minoxidil (2020)
Dermatologists from two Thai universities compared a hair lotion containing acetyl tetrapeptide 3, biochanin A, ginseng, and sage oil with 3% minoxidil for 24 weeks. 32 people participated, 16 men and 16 women. The study was triple-blind and received no funding from a manufacturer.
- The number of thick hairs increased by 8.3% in the herbal group and by 8.7% in the minoxidil group. That difference was not significant.
- There were no side effects in the herbal group. One woman in the minoxidil group developed eczema on her scalp.
That is a decent result. Two caveats: there was no placebo group, and the lotion also contained ginseng and sage. So you don't know what part of the effect comes from Capixyl. The researchers themselves wrote that larger and longer studies are needed.
3. The Turkish study with a combination (2019)
Here, 120 men were given 5% minoxidil or a lotion with Redensyl, Capixyl, and Procapil for 24 weeks. Of the 106 men who completed the study, 64.7% in the combination group saw moderate to strong recovery, compared to 25.5% with minoxidil. Striking, but here too you are testing a mix and not Capixyl alone. You can read more about the other two in Redensyl for hair loss and Procapil explained.
Our honest verdict on the evidence
Capixyl has more support than most "natural" remedies, but less than minoxidil or finasteride. In summary:
- The mechanism of action is logical and addresses two things: DHT and hair anchorage.
- There is one small placebo study, and it comes from the manufacturer.
- The independent studies consistently tested a combination. Those combinations performed well, even against minoxidil.
- There is no study that lasted longer than six months.
We therefore see Capixyl as a strong component of a formula, not as something you should rely on exclusively. The fact that it scores well in independent research primarily in combinations is consistent with this.
Red clover and estrogen: should you worry?
Biochanin A is a plant estrogen: a plant substance that somewhat resembles the female hormone estrogen. That is why men on forums ask whether a serum with red clover can make them "more feminine."
As far as is known, there is no reason for this. A few things to consider:
- It concerns a small amount of extract in a product that you apply to a small piece of skin.
- In the studies, no hormonal side effects were reported, only occasional itching or redness.
- How much biochanin A enters your blood through the scalp has never been measured. You should know that honestly.
- Red clover has been taken as a dietary supplement for years, in much higher quantities, without this leading to major problems in men.
If you are very cautious about hormones, for example due to a medical condition, consult your GP.
Who is Capixyl for?
Capixyl is best suited for men with early or moderate hair loss, approximately Norwood 2 to 4. That is the group that participated in the studies. Your hair follicles must still be functioning: you won't get hair back on a spot that has been bald for years with this. See also when is hair loss still reversible.
It is also an option if you cannot tolerate minoxidil or do not want to use medication. And because it works via a different route, you can use it alongside minoxidil or finasteride.
Don't expect quick results. In all studies, measurements were taken after four to six months. You can read why it takes so long in how long does it take for a hair serum to work.
What to look for in a product with Capixyl?
- Leave on, not shampoo. The studies used lotions that were left on. You wash a shampoo off after a minute.
- The quantity. The manufacturer tested 5%. Many brands do not mention the percentage. The further down the list, the less it contains.
- What else is in it. The independent evidence comes from combinations. A product with only Capixyl is therefore less well-researched than a mix.
In our own Hairborn Growth Serum, Capixyl is one of the twelve ingredients in the new formula. It is included alongside, among others, the Hairborn Complex (based on Redensyl), Procapil, AnaGain, adenosine, and caffeine. That is intentional: the combinations from the studies are also the combinations that score the best. If you want to improve absorption, you can use a derma roller once a week. How to do that safely is in combining derma roller and serum.
In short
Capixyl is a combination of a peptide and red clover that inhibits DHT in the lab and anchors hair more firmly. One small study by the manufacturer with a placebo group was positive. Independent research only did so with combinations, and they held up well against minoxidil. It is well-tolerated and logical as a building block in a serum. We would not sell it as a miracle cure for a bald crown.
Frequently asked questions
What exactly is Capixyl?
Capixyl is a cosmetic ingredient consisting of the peptide acetyl tetrapeptide 3 and a red clover extract. It was developed by Lucas Meyer Cosmetics and is incorporated into hair serums and lotions. On the ingredient list, it is usually listed under those two separate names. It is not a medicine, so you don't need a prescription for it.
Does Capixyl block DHT like finasteride?
No, not in the same way and certainly not as strongly. Biochanin A from red clover inhibits the enzyme that produces DHT, but that has only been demonstrated in the lab. Finasteride lowers DHT throughout your entire body by about two-thirds, and that is well-measured. With Capixyl, the effect on DHT in the scalp has never been measured in humans.
Is Capixyl better than minoxidil?
You cannot say that based on current research. In a Thai study, a lotion with Capixyl ingredients scored just as well as 3% minoxidil, and in a Turkish study, a combination with Redensyl and Procapil performed better than 5% minoxidil. But both studies were small, tested a mix, and had no placebo group. Minoxidil has much more and larger research behind it.
How long does it take for Capixyl to work?
Expect at least three to six months before you see anything. The manufacturer's study measured after four months, the independent studies after six months. Your hair grows about a centimeter per month, and a hair follicle that returns to the growth phase only produces a visible hair after months. Stopping after a few weeks is therefore too soon.
Does Capixyl have side effects?
Capixyl rarely causes side effects. In the studies, no serious complaints were reported, and in the Thai study, no one in the Capixyl group suffered from scalp issues. Itching, redness, or flakes can occur, often due to other substances in the product such as alcohol or perfume. Stop if your scalp becomes irritated.
Does Capixyl cause shedding in the beginning?
There is no research showing a shedding phase with Capixyl. With minoxidil, temporary increased hair loss is known in the first weeks. With Capixyl, this has not been described, nor has it been specifically researched. If you see a bit more hair in the shower in the first weeks, it could also be seasonal. More about that in our blog on shedding.
Can you combine Capixyl with finasteride or minoxidil?
Yes, you can, and there are no known problems with that combination. Capixyl works on hair anchorage and through mild DHT inhibition in the scalp, which complements what medication does. There is just no study that has measured how much extra it provides. Preferably apply a serum and minoxidil at different times of the day.
What is the difference between Capixyl and Redensyl?
They address a different part of the problem. Redensyl focuses on the stem cells in the hair follicle and aims to get dormant follicles working again. Capixyl inhibits DHT in the scalp and strengthens the scaffolding around the hair root. That is why they are often together in one product, and the independent studies also tested them together.
Does Capixyl also work for women?
Probably yes, but the evidence is limited. In the Thai study, half of the participants were women, and the results applied to the entire group. No separate research has been conducted solely on women. Women who are pregnant or breastfeeding should preferably consult their doctor first, as red clover contains plant estrogens.
How much Capixyl should be in a serum?
The manufacturer tested a lotion with 5% Capixyl, and that is the amount often cited as a guideline. There is no research showing what the lowest effective concentration is. Many brands do not state the percentage. In that case, look at the ingredient list to see how far up acetyl tetrapeptide 3 and red clover appear.
