Most hair masks in the drugstore aisle contain silicone, fragrance and a long list of things that feel luxurious for 20 minutes and do nothing long-term. When we built Rehues Steam Repair Mask, we asked a harder question: what actually repairs damaged hair?
The answer pulled us into two traditions — Traditional Chinese Medicine for Ligusticum, and modern cosmetic science for amino acids and hydrolysed keratin. Here’s exactly what’s inside, and why each ingredient earns its spot.
The formula at a glance
- Ligusticum Chuanxiong (川芎) — scalp circulation and follicle support, rooted in 1,000 years of TCM practice.
- 11 Amino Acids — replenish the keratin building blocks bleach, heat and UV destroy.
- Hydrolysed Keratin — small-molecule protein that actually penetrates the cortex.
- Vitamin E (Tocopherol) — antioxidant shield, moisture and shine.
- Imported PCA Core — natural moisturising factor; keeps oil and hydration balanced.
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1. Ligusticum Chuanxiong (川芎) — the TCM root with modern credentials
Ligusticum Chuanxiong — nicknamed Chuanxiong — is a rhizome used in Chinese medicine since at least the Tang Dynasty. In TCM it’s classed as a blood-moving herb: it’s thought to stimulate circulation and clear stagnation. Chinese herbalists have long used it topically and internally for scalp and hair-related concerns.
Modern research is catching up. A 2025 study in the journal Natural Product Communications found that Ligusticum sinense ‘Chuanxiong’ leaf essential oils promoted hair growth in animal models without acute toxicity. Ingredient databases now classify Ligusticum chuanxiong root extract as a botanical active with benefits for scalp circulation and overall hair health.
What this means in Rehues: healthier scalp environment → better follicle function → stronger new growth over time. Ligusticum isn’t a one-session miracle; it’s a long-term scalp investment you apply via mask.
2. 11 Amino Acids — the keratin building blocks your hair lost
Your hair is about 95% keratin, a protein made up of amino acids chained together by disulphide bonds. Bleach cleaves those bonds. Heat and UV denature them. Over time, damaged hair has fewer intact amino acid chains — which is why it feels weaker, less elastic, and breaks more easily.
Delivering amino acids back to the hair shaft — especially through an opened cuticle under steam — helps replenish what’s been lost. The 11 amino acids in Rehues include building blocks like cysteine (crucial for disulphide bond formation), glycine, glutamic acid and arginine. Together they help restore strand strength and flexibility.
3. Hydrolysed Keratin — small enough to actually penetrate
Standard keratin is a huge protein. It sits on the surface of the hair, gives temporary smoothness, and washes off. Hydrolysed keratin is keratin that’s been broken down into shorter peptide chains — small enough to slip past the cuticle and into the cortex where structural repair actually happens.
Pair hydrolysed keratin with steam-opened cuticles and amino-acid co-actives, and you get genuine structural repair, not just a silicone-style coat-and-wash-off effect.
4. Vitamin E (Tocopherol) — the antioxidant shield
Vitamin E neutralises free radicals from UV and pollution, the ambient enemies of colour and shine. Topically, it also adds hydration and softness to the hair fibre. Think of it as the moisturiser that seals everything in.
5. Imported PCA Core — moisture, but balanced
PCA (pyrrolidone carboxylic acid) is a natural moisturising factor already present in human skin and hair. It holds onto water without over-saturating the strand — crucial in humid Singapore, where over-moisturised hair can feel limp. PCA keeps the moisture-oil balance steady.
How these five ingredients work together
Each active on its own does something useful. Together, under steam activation, they create a compounded repair effect:
- Steam lifts the cuticle.
- Hydrolysed keratin + amino acids travel into the cortex and rebuild.
- Vitamin E shields against oxidation during the process.
- PCA balances moisture.
- Ligusticum works on the scalp for long-term follicle support.
- As hair cools, the cuticle closes — sealing everything inside.
This is why seven minutes of Rehues steam mask delivers more than 30 minutes of a conventional mask. It’s not the time. It’s the chemistry.
What we don’t use
We left these out of the formula intentionally:
- PPD — the #1 box-dye allergen.
- Ammonia — cuticle-raiser for permanent dyes.
- Peroxide — oxidiser for permanent dyes.
- Sulfates (SLS, SLES) — colour-stripping surfactants.
- Animal-derived ingredients.
- Heavy silicones that build up and weigh hair down.
Where to find the full ingredient list
Full INCI ingredient declaration lives on the Rehues Steam Repair Mask product page. If you’re researching specific allergens or pregnancy-safe formulations, we publish everything — no hidden components. Email us anytime.
FAQs
Is Ligusticum safe for sensitive scalps? It’s a mild botanical in the concentrations we use, and traditionally considered soothing. A 48-hour patch test is still smart for first-time users.
Can I use it if I’m pregnant? The formula contains no PPD, ammonia or peroxide. Talk to your doctor about Ligusticum specifically if you’re in your first trimester.
Is it halal? No animal-derived ingredients; not halal-certified. See our safety FAQ for details.
Where is it made? Formulated and packaged in Asia with imported pharmaceutical-grade actives.
Try the formula: Rehues Steam-Activated Glossy Hair Repair Mask.
Related reads: Does a Steam Hair Mask Actually Work? The Science • “My Hair Feels Like Straw” — 7-Minute Rescue • Is Colour-Depositing Shampoo Safe? PPD, Ammonia & Pregnancy Q&A
