Thioglycolic acid vs cysteamine eyebrows
Thioglycolic acid vs cysteamine – choosing the right active
TECHNICAL COMPARISON & SALON PROTOCOLS
What you need to know in 30 seconds
Brow lamination uses two main actives: thioglycolic acid (TGA) works in 3-8 minutes on all hair types with a sulphurous odour; cysteamine takes 5-10 minutes, suits fine hairs and sensitive skin, with no smell. The Brow Bomb system combines ethanolamine thioglycolate + vegan keratin to restructure brows for 6-8 weeks. Patch test mandatory 24-48 hours before any treatment per UK beauty standards.
Thioglycolic acid (tga): the fast-acting option
Thioglycolic acid breaks the disulphide bonds in the hair to restructure it. Professional products use ethanolamine thioglycolate, which is more stable and less volatile than the ammonium form.
| Hair type | Processing time (TGA) |
|---|---|
| Very fine brows | 3-4 min |
| Fine or previously tinted | 4-5 min |
| Normal healthy brows | 5-6 min |
| Thick/coarse brows | 6-8 min |
Maximum concentration allowed in UK: 11% for professional use only (salons, clinics), following EU retained regulations.
Advantages of TGA
- Fast action = less treatment room time
- Effective on all hair types, even the most resistant
- Optimised client rotation (8-10 treatments/day possible)
Disadvantages
- Sulphurous smell ("rotten egg") noticeable from sachet opening
- Risk of over-processing if timing exceeded (breakage, weakening)
Cysteamine: the gentle alternative
Cysteamine hydrochloride works progressively, like a treatment that slowly penetrates the hair. It suits clients with sensitive skin, delicate eyes, or seeking a premium spa experience.
| Hair type | Processing time (Cysteamine) |
|---|---|
| Very fine brows | 5-6 min |
| Fine/previously treated | 6-8 min |
| Normal brows | 8-10 min |
Advantages
- No unpleasant odour
- Enhanced safety margin = less risk of over-processing
- Ideal for beginners or gentle "Korean-style" protocols
Limitations
- Ineffective on very thick/coarse brows (early drop after 3-4 weeks)
- Longer processing time = reduced client rotation
The brow bomb system
Brow Bomb is a 3-step protocol combining restructuring, neutralisation and repair.
Step 1 – lifting cream (restructuring)
Main active: Ethanolamine thioglycolate (stabilised TGA form) | pH: 9 to 9.5 (alkaline).
Includes Urea (penetration), Biotin (strengthening), Niacinamide (growth/soothing), and Vegan Keratin (hydrolysed plant proteins) to repair during restructuring.
Step 2 – setting lotion (neutralisation)
Neutralising protocol : Sodium bromate (fixes shape by reforming disulphide bonds) | pH: 6-6.5 (closes cuticles).
Contains hyaluronic acid, panthenol, and liquorice extract. Time: 5-6 min mandatory.
Step 3 – moisturising serum (repair)
Neutral pH (5-6) featuring aloe vera, arnica, rosemary, and plant proteins. Application: generous layer without rinsing = protective film for 24h.
GMP 2022 certification + CPNP registered (legal EU/UK commercialisation).
Absolute contraindications
- Pregnancy and breastfeeding (precautionary principle)
- Active skin conditions: Eczema, psoriasis, herpes, dermatitis
- Eye infections: Conjunctivitis, stye, blepharitis (wait 2 weeks post-recovery)
- Recent eye surgery: Minimum 6 weeks delay after LASIK/PRK
- Recent microblading/tattoo: Wait < 4 weeks (risk of pigment migration)
- Skin lesions: Cuts, sunburn, abrasions or positive patch test
Patch test: legal requirement
The sensitivity test 24-48 hours before treatment is mandatory per UK National Occupational Standards.
- Apply a rice grain-sized amount of Step 1 to the inner elbow or behind the ear.
- Leave exposed to air without rinsing.
- Observe for 24-48h: redness, itching, swelling, or burning sensation.
Essential: Informed consent form signed by client must be retained for minimum 5 years.
Complete salon protocol (15 steps)
- Consultation + anamnesis: history, allergies, expectations.
- Patch test (if 1st treatment, 24-48h before).
- Before photos (face + profiles).
- Cleansing: oil-free makeup remover + complete drying.
- Hair texture assessment.
- Bonding serum application on brows + silicone pad.
- Step 1 application: thin layer (3-8 min).
- Step 1 removal: renewed damp cotton bud (no water).
- Step 2 application: generous layer (5-6 min mandatory).
- Step 2 removal: damp cotton bud + gentle lukewarm rinse.
- Optional tinting (1-3 min).
- Optional shaping (wax or tweezers).
- Step 3 application: generous layer without rinsing.
- After photos.
- Aftercare sheet + disposable spoolie.
Aftercare: client instructions
First 24-48h (critical)
- No water contact: No facial shower, sauna, pool, or intense sport.
- Zero cosmetics: No cream, serum, oil, or makeup on brows.
- Don't touch/rub: Avoid direct heat (hairdryer, sunbeds).
Daily maintenance (from 48h onwards)
- Brush morning + evening upward then outward.
- Castor oil 2-3×/week in the evening to nourish.
- Touch-up timing: Between 6 and 8 weeks post-treatment (Under 6 weeks = cumulative weakening).
Profitability for your salon
Average UK pricing 2026: £43-48 (Full package). London/South East can reach £48.
Gross Margin: Material cost (single-use sachets) is approximately £2.50-5 per treatment. On a £40 price point, your gross margin is 87-93% (£35-37.50) before overheads.