Encyclopedia · botanical
Redensyl
Redensyl is a branded cosmetic blend marketed to wake follicle stem cells, with one small vehicle-controlled trial in a blend and several maker-linked open-label studies.
What it is
Redensyl is a patented ingredient blend sold by a raw-material supplier. It appears in "hair density" serums, often alongside rosemary, caffeine or peptides (Bikash 2025). It is a cosmetic in the US, EU and UK.
How it works
The marketing claim is activation of stem cells in the outer root sheath of the follicle. This mechanism is reported by the supplier, and no independent primary mechanism data are available for it.
What the studies show
- In 44 people a lotion containing Redensyl plus a second active (Sepicontrol A5), used twice daily for 24 weeks, raised the median anagen-to-telogen ratio from 2.25 to 6.02 versus vehicle and improved self-assessment, with excellent safety. It is a blend, so Redensyl's own share is unclear. Katoulis 2020
- In 54 men having PRP sessions, Redensyl plus saw palmetto and biotin beat Procapil on pattern hair loss grade (P<0.05). Neither was compared with PRP alone. Tr 2023
- A 120-day open-label study of a multi-active rosemary and Redensyl serum reported large percentage improvements with no control group. It was funded by the product maker. Patel 2025
- A 60-day open-label study of 32 people using a serum with Redensyl, AnaGain, Procapil and other actives reported a 31.6% higher hair growth rate, with no control and company links. Merja 2024
- A 2025 review found studies of such actives are mostly small, on combined formulas, conflicted and rarely against standard therapy. Bikash 2025
How it's used in studies
A twice-daily lotion in the Greek trial for 24 weeks and a once-daily serum in the open-label studies. Concentrations were not stated in the abstracts.
Side effects and safety
No significant adverse events were reported in these trials.
Bottom line
Redensyl is a plausible low-risk add-on, but no study shows it beats placebo as a single ingredient or matches minoxidil. Choose a serum on price and tolerability, and keep the proven treatment if you need results. Independent single-ingredient trials are missing; most data come with commercial ties. See cosmetic hair growth serums.
Studies 5
Katoulis AC et al. A randomized, single-blinded, vehicle-controlled study of a topical active blend in the treatment of androgenetic alopecia. Dermatol Ther. 2020
Tested: lotion with Redensyl and Sepicontrol A5 twice daily vs vehicle
Result: Median anagen:telogen ratio rose from 2.25 to 6.02 and self-assessment improved; the blend means Redensyl's own share is unclear.
Read the study ↗Tr P et al. A comparative study of topical Procapil with PRP versus topical Redensyl, saw palmetto, and biotin with PRP in androgenetic alopecia. Cureus. 2023
Tested: Procapil plus PRP vs Redensyl, saw palmetto and biotin plus PRP
Result: The Redensyl combination did better on androgenetic alopecia grade (P<0.05); neither was compared with PRP alone.
Read the study ↗Patel M et al. Soulflower Rosemary Redensyl Hair Growth Serum (Tetragain) clinical evaluation. Cureus. 2025
Tested: multi-active rosemary and Redensyl serum, open-label single arm
Result: Large percentage improvements with no control group; funded by the product maker.
Read the study ↗Merja A et al. Safety and efficacy of REGENDIL infused hair growth promoting product. J Cosmet Dermatol. 2024
Tested: serum with Redensyl, AnaGain, Procapil and other actives, open-label
Result: Hair growth rate rose 31.6% at day 60; no control group and company-linked.
Read the study ↗Bikash C. Topical alternatives for hair loss: beyond the conventional. Int J Trichology. 2025
Tested: Redensyl, Capixyl, Procapil, Baicapil, AnaGain and similar actives
Result: Evidence is mostly small studies of combined formulas, often conflicted and rarely compared with standard therapy.
Read the study ↗Related
- ProcapilProcapil is a branded trio of a biotin-linked peptide, apigenin and oleanolic acid sold as a hair-anchoring active, with small studies that are mostly add-ons to other treatments.
- CapixylCapixyl is a branded blend of a peptide and a red clover isoflavone; one tiny trial of a similar blend matched 3% minoxidil, with no placebo arm.
- AnaGainAnaGain is a pea sprout extract with a small maker-run study and mouse data, plausible and low risk but without an independent controlled trial.
- Caffeine (topical)Caffeine in shampoos and leave-on liquids clearly stimulates hair follicles in the lab, but the human trials are small, mostly industry-run and mostly on blends.
- MinoxidilThe most widely used hair-growth treatment, available as a cheap over-the-counter lotion or foam and as a prescription tablet, with a mechanism that is still only partly understood.