Redensyl for Hair: What Is in It, How It Works and What Was Tested

Redensyl is a hair ingredient made by Givaudan Active Beauty from four parts: a larch-wood polyphenol called DHQG, a green tea polyphenol called EGCG2, and two nutrients, glycine and zinc. It is built around one idea. In a thinning scalp, the cells that start each new growing phase become sluggish, and Redensyl's main part, DHQG, is designed to restart them. The rest of the blend calms the scalp and supplies the work of building hair.

What is in Redensyl

You will rarely see "Redensyl" in an ingredient list. Like most branded actives, it appears as its separate parts. The supplied ingredient is mostly water and glycerin, with a little sodium metabisulfite, and four working parts.

Swipe to see all four columns →

A glucoside is a molecule with a glucose sugar attached. Givaudan describes both polyphenols as "stabilised" and the blend as water soluble. Plant polyphenols like these tend to break down easily, and attaching a sugar is a common way to make such molecules sturdier and easier to dissolve, so they can sit in a clear serum. Givaudan recommends using Redensyl at 1 to 3% of a finished product.

The two cells Redensyl is built for

To see why Redensyl is designed the way it is, start with how a hair gets started.

Every follicle cycles. A long growing phase (anagen), which can last years on the scalp, ends in a short transition, then a resting phase (telogen) of a few months. When the old hair sheds, the follicle has to rebuild its lower half and start a new hair. Two kinds of cells run that restart.

• Stem cells in the outer root sheath. Along the side of the follicle sits a pocket called the bulge, holding a reserve workforce of stem cells. At the start of each cycle they divide and supply the cells that rebuild the follicle and make the new hair.
• The dermal papilla. At the base of the follicle is a cluster of signaling cells with its own blood supply. Think of it as the control room: it tells the stem cells when to start and how big a hair to build.

The two talk to each other, and that conversation decides when a new growing phase begins. Givaudan's rationale is that in hair loss both sides weaken: the stem cells are less productive, and the dermal papilla communicates with them less effectively. The resting phase drags on, starting a new growing phase becomes sluggish, and a larger share of hairs sit in telogen at any time.

DHQG: restart the growth cells

DHQG is Redensyl's main part; Givaudan calls it the major component. Givaudan tested it on stem cells taken from the outer root sheath and grown in a dish, and measured four things.

• Division. Stem cells divided more as the DHQG dose rose from 2 to 50 micromolar (µM), measured by how much of a marker the dividing cells took up.
• Stem identity. At 10 µM, the cells made almost twice as much of the message for cytokeratin 15 (K15), a protein that marks a cell as a true stem cell. This matters because dividing alone is not enough: a reserve that divides and loses its stem character is used up. The result suggests the cells multiplied and stayed a reserve.
• Survival. At 10 µM, the message for BCL2 doubled. BCL2 is a survival signal: it holds off apoptosis, the programmed cell death that clears cells away.
• Growth signal. At 2 µM, the message for beta-catenin rose more than threefold. Beta-catenin is a central signal inside follicle cells for starting a growing phase; Givaudan describes it as pushing the stem cells toward anagen.

On the other side of the conversation, Givaudan grew human dermal papilla cells for 48 hours with DHQG at 2 to 50 µM and found their metabolic activity rose, a measure of how hard the cells are working.

All of these are cell results: single cell types in a dish, measured as messages and activity over hours or days. They show what DHQG does to the cells it is aimed at. They do not show hair growth on their own.

Independent work points the same way for the plain molecule. Park and colleagues (2022) tested taxifolin, the same molecule as dihydroquercetin without its sugar, on dermal papilla cells and reported that it helped regulate cell death in those cells and raised IGF-1, a growth signal. That is taxifolin, not Redensyl's glucoside form, and again a cell study.

EGCG2: calm the scalp

EGCG2 is the green tea part. A scalp with pattern hair loss often shows low-grade inflammation, so Givaudan tested whether EGCG2 could quiet it. They stressed human skin cells (keratinocytes) with IL-1 beta, an inflammatory trigger, then measured IL-8, a messenger cells release to call in an inflammatory response. With 8 µM EGCG2 for 48 hours, IL-8 fell 21%. Givaudan also describes EGCG2 as capturing free radicals.

Plain EGCG has its own hair research. In 2007, a Seoul National University team (Kwon and colleagues) found that EGCG increased hair growth in human scalp follicles kept alive in the lab and increased division of dermal papilla cells. Those results are for plain EGCG, not the glucoside in Redensyl, but they show green tea's main polyphenol acts on the same control-room cells.

Glycine and zinc: supply the build

The last two parts are building support. Glycine is a major part of the keratin-associated proteins that pack around keratin fibers inside the hair shaft. Zinc is a cofactor, a helper many enzymes need; Givaudan cites its role in building cystine, the sulfur-rich amino acid that cross-links keratin, into the hair. Neither was tested on its own in the Redensyl work. They are there so a follicle that has restarted has what it needs to build.

What the research tested

Here are the tests Givaudan reported for Redensyl itself, sorted by model.

Swipe to see all five columns →

The follicle test. Givaudan took scalp follicles from four men with hair loss and kept them alive in culture, a standard lab method (the Philpott model) that lets a follicle keep growing a hair for days. Follicles got Redensyl at 1%, minoxidil at 1% as a benchmark, or nothing, and hair length was measured from photos at days 7 and 10. The leaflet reports hair growth 214% greater than untreated follicles for Redensyl, and 118% greater for minoxidil. This is a useful bridge between cells and people: whole human follicles, not single cells. It is also a short test of hair already growing, so it does not show the restart of a resting follicle.

The 3-month study in men. Twenty-six men aged 18 to 70 with moderate pattern hair loss took part. The leaflet calls it clinical grade 3 to 4 without naming the scale. On the Norwood-Hamilton scale, the standard seven-stage scale of male pattern loss from I (no recession) to VII (extensive loss), stages III and IV mean clear temple recession, often with crown thinning. The test was double-blind and placebo controlled: neither the men nor the investigators knew who had which lotion. To enter, each needed at least 150 hairs and 40 resting hairs per square centimeter on the test area. They applied 3% Redensyl or a placebo to the whole scalp once a day for three months.

Progress was measured by phototrichogram: a 1.5 square centimeter patch of scalp is shaved, and close-up photos of a 0.7 square centimeter window inside it are analyzed to sort the hairs into growing and resting. Photos were taken at the start, at one month and at three months. After three months in the Redensyl group:

• the share of hairs in the growing phase rose 9% from the start;
• the share in the resting phase fell 17%;
• the ratio of growing to resting hairs reached 2.37, up 29%;
• density rose 8% on average.

The placebo group showed a small early change that Givaudan describes as not significant and attributes to mechanical stimulation of scalp circulation from applying it, then little change after the first month. Givaudan reports that 85% of the Redensyl volunteers improved.

That is the only study of Redensyl alone in people, and it was run by the maker.

Redensyl in combinations

Every published study of Redensyl in people since has used it in a blend. Each is useful, but each tests the blend, not Redensyl.

• Redensyl with cinnamon bark extract. Katoulis and colleagues (Dermatologic Therapy, 2020) randomized 44 men and women with pattern hair loss to a lotion of Redensyl plus Sepicontrol A5, a cinnamon bark extract, or the lotion base alone, twice daily for 24 weeks; 41 finished. In the active group, the median ratio of growing to resting hairs rose from 2.25 at the start to 4.00 at 12 weeks and 6.02 at 24 weeks.
• Redensyl with PRP. A 2023 study in Cureus treated 54 men with platelet-rich plasma (PRP) injections every three weeks, plus a daily topical: either Redensyl with saw palmetto and biotin, or Procapil. Graded on the Norwood-Hamilton scale over about six months, the Redensyl group's mean improvement was 21.9%, versus 11.9% for the Procapil group. Both groups also had four PRP sessions. For Procapil itself, see Biotin-GHK and Procapil explained.
• A multi-ingredient serum. A 2025 Cureus study followed women using a serum with Redensyl, AnaGain, rosemary and other actives for 120 days, with no comparison group. Measured by phototrichogram, the ratio of growing to resting hairs rose 48% by day 90.
• RCP. Karaca and Akpolat (2019) compared the RCP combination of Redensyl, Capixyl and Procapil with 5% minoxidil, as separate treatments, in 120 men over 24 weeks; 106 finished. Our guide to RCP covers that study.

The pattern is consistent with how Redensyl is used: as one part of a formula, not as a treatment on its own.

Why Redensyl sits inside RCP

Redensyl covers one job well: restarting the growth cells so a new growing phase starts, the job the RCP guide calls "start new growth". It does not target DHT, the hormone that keeps shortening growing phases in pattern hair loss, and it does not rebuild the proteins that anchor a long-growing hair in place.

Those are the other two jobs in RCP. Capixyl and Procapil each rebuild the follicle's anchor and each carry a plant compound aimed at the enzyme that makes DHT. Redensyl restarts the growth cells; its partners hold the follicle and turn down the DHT signal. The RCP guide shows how the three fit together on one follicle.

What to expect, and when

Redensyl's own human study measured at three months, and the combination studies ran from 120 days to about six months. That timing follows from the cycle: a resting follicle has to start a new growing phase, and the new hair has to grow long enough to see. Nothing in the research suggests a change in days.

Loxstar's product page says most users see "reduced shedding by week 4, thicker hair by week 8, and new growth by week 12," and recommends at least 90 days of daily use. To judge your own progress fairly, take photos on a schedule; our progress photo guide shows how to keep them comparable.

Redensyl in Loxstar

Redensyl is one of the named actives in the current Loxstar Peptide Hair Growth Serum, and you can find its parts in the ingredient list: Larix Europaea Wood Extract, Camellia Sinensis Leaf Extract, Glycine and Zinc Chloride. It is the part of RCP that restarts the growth cells, alongside Capixyl and Procapil, and the formula adds AnaGain, a pea sprout extract researched for the signals that start a growth phase, and liposomal caffeine. For every ingredient and its role, see the Loxstar formula map.

The routine is simple: once a day on a clean, dry scalp, a pea-size amount on thinning areas, 30 seconds of massage, then about five minutes before styling.