What's in hair dye
Most permanent dyes contain:
- Oxidizers (hydrogen peroxide) — lifts/deposits color
- Alkalizers (ammonia or ethanolamine) — opens cuticle
- Developers — activate pigment
- Dye precursors (PPD, PTD, resorcinol) — form color inside hair
- Conditioning agents — try to offset damage
Each can cause issues.
PPD — the allergen to know
P-phenylenediamine (PPD) is the main precursor in dark permanent dyes. Effective, but:
- One of the most common contact allergens
- Sensitization increases with repeated exposure
- Reactions can be severe (scalp swelling, blisters, hospital-worthy cases)
- Once sensitized, you're allergic for life
Alternative: PTD (toluene-2,5-diamine) — similar chemistry, cross-reacts but sometimes tolerated. Some brands use it instead.
Patch test — seriously
Box dyes include instructions. Most people skip them. Don't:
- Apply a small amount of mixed dye behind the ear
- Wait 48 hours
- No reaction → proceed with confidence
- Itching, redness, burning → don't use this dye
Do this every time, not just once. Sensitization can develop suddenly.
Ammonia vs ammonia-free
Ammonia: Strong alkalizer, effective, smells terrible, can irritate scalp and lungs.
Ethanolamine (ammonia-free): Milder alkalizer. Less irritating, but:
- Takes longer
- Can be more drying on hair (higher pH)
- Still raises cuticle significantly
"Ammonia-free" isn't automatically gentler — it depends on the formulation.
Semi-permanent vs permanent
Semi-permanent
- No oxidation, no lift
- Coats hair instead of penetrating
- Washes out in 4–12 shampoos
- Much less damaging
- Good for experimentation
Demi-permanent
- Uses low-volume peroxide (10 vol)
- Mild lift
- Lasts 4–8 weeks
- Less damage than permanent
- Good for going darker or blending grays
Permanent
- 20–40 volume peroxide
- Permanent color change
- Most damage potential
- Lasts until grown out
Safer dye choices
Plant-based (henna, indigo)
- Not chemical, but not harmless
- Henna + indigo = brown/black
- Real henna doesn't contain PPD
- Mixed commercial hennas often do contain PPD — read labels
- Henna coats hair; hard to color-correct later
Low-ammonia formulas
- Most professional lines now have them
- Look for brands like Redken Shades EQ, Goldwell Colorance
Oxidative-free toners
- Deposit-only, wash out gradually
- Good for refreshing without full color
When to avoid dye
- Active scalp irritation or conditions
- Pregnancy (avoid first trimester at minimum; limited evidence but precaution)
- Within 2 weeks of another chemical treatment
- If you've had severe allergic reaction before
Protect your hair during color
- Deep condition 2–3 times the week before
- Ask for a Olaplex No.3, K18.">bond-builder in the mix (Olaplex No.1, K18)
- Don't overlap new dye on previously colored lengths
- Use a gentle clarifying shampoo the day before (removes minerals that interfere)
Aftercare
- Wait 72 hours to wash
- Sulfate-free, color-safe shampoo
- Cool water only
- Weekly bond-builder or protein mask
- UV protection outdoors
Where Mutaly applies
Dye history is tracked in the Mutaly quiz — chemically colored hair gets routine adjustments for porosity, damage, and color preservation.