Peptide and Redensyl Serums, Read Against Their Own Studies

Redensyl, Procapil, AnaGain, Capixyl, Baicapil, Capilia longa. These are trade names for cosmetic actives, sold to formulators rather than to you, and they are the reason a serum bottle can read like a pharmacology textbook while promising nothing in particular. On this site's scale the group scores four out of ten, which is thin, and the reason is worth understanding because it applies to almost every serum on sale.

What these ingredients actually are

They are branded cosmetic raw materials. A supplier develops a blend — a peptide, a plant extract, a glycoside — gives it a trade name, publishes a technical file, and sells it to brands who print the name on the front of a bottle. The name on your serum is therefore a purchasing decision by a formulator, not a finding by a researcher, and the technical file is marketing literature written by the party with the most to gain.

That is not a reason to dismiss them. It is a reason to ask, for each one, whether anybody outside the supply chain has ever tested it on people with hair loss.

The study that exists

Merja and colleagues published a safety and efficacy study in the Journal of Cosmetic Dermatology in 2024 of a hair serum containing Redensyl, AnaGain, Procapil and Capilia longa together with 5 kilodalton hyaluronic acid, under the trade name REGENDIL. Thirty-two healthy adults aged 18 to 45 with hair-fall complaints applied the product daily for 60 days. The paper reports a growth-rate increase of 10.52% at 30 days and 31.62% at 60, measured with a CASLite-Nova instrument, and no product-related adverse events.

Now the parts that decide a grade. There was no control group and no placebo: every participant received the product, so there is nothing to compare the change against. The authors are listed as being from NovoBliss Research, a contract research organisation, and Anveya Living, the company behind the product. An erratum was published in the same journal in 2025. And four actives were tested in one formula, so even if the change were real, the study cannot attribute it to Redensyl or to any other single ingredient.

One point on our first question — an uncontrolled study. Zero on who paid. Two on what was counted, because an instrument measured growth rate rather than a questionnaire asking about it. One on the fourth question, because a serum with only one of those four actives is not the formula that was tested. Four out of ten.

What an independent reviewer found

A 2025 review in the International Journal of Trichology went through this exact class — Redensyl, Procapil, Capixyl, Baicapil, AnaGain, onion juice, coffee extract, saw palmetto extract, pumpkin seed oil and rosemary oil — pulling twenty-four articles and technical files. Its author, a dermatologist at a regional institute in Shillong with no declared conflicts of interest, described the field bluntly: hair growth serums, oils and shampoos have flooded the cosmeceutical market, and the masses are targeted with sponsored marketing through social media.

Most of the studies have limited sample size, lack of comparison with standard therapies, nonuniformity between study groups, nondisclosure of the type of alopecia treated, and conflicts of interest. — International Journal of Trichology, 2025

The review's own conclusion is measured rather than dismissive: these topicals, with their mild side-effect profiles, may find a use as an add-on or as an alternative for people who cannot tolerate standard therapies. That is a reasonable place to land, and it is a long way from what the bottles imply.

The Nanoxidil question

One branded serum active on this site carries no grade at all. A PubMed search for Nanoxidil returned no records on 24 September 2026 — not a weak study, not a company-funded one, nothing. That is a statement about the published literature and not about whether the product does anything, and it applies to an ingredient sold by a company whose links appear elsewhere on this site. It stays ungraded, because a scale that can be embarrassed by its own partners is the only kind worth publishing.

How to read a serum's ingredient list

• Find out whether the named active has a human study at all, and where it was published.
• Check for a control group. Without one, an improvement over 60 days is a description of 60 days, not of the product.
• Check who the authors work for. A contract laboratory plus the brand is a different kind of paper from a university dermatology department.
• Check whether the tested formula is the formula you are buying. Four actives together are not one active alone.
• Treat percentage improvements with the same suspicion you would apply to any number generated by the party selling the product.

Where these serums sit against the medicated shampoos, on the same scale, is in the best shampoo for hair loss, graded on published evidence. For the ingredient with the single most-quoted and least-understood trial, read what the rosemary oil versus minoxidil trial actually found.