Grey Hair & Sensitive Scalp: Causes, Care, and Gentle Colour Solutions

Grey hair often shows up with new challenges — not just in colour, but in comfort.
Many people notice that as hair turns grey, their scalp becomes more reactive, traditional dyes feel harsher, and results become less predictable.

If you’ve experienced irritation after colouring, struggled with uneven coverage, or felt unsure about labels like PPD-free or ammonia-free, you’re not alone. This guide explains why grey hair behaves differently, why sensitive scalps react, and how to approach grey coverage more gently — before committing to any routine.

Why Grey Hair Behaves Differently

Grey hair isn’t just pigmented hair without colour. Structurally, it changes.

As melanin production slows, the hair cuticle often becomes tighter and more compact. This can make grey hair:

• More resistant to colour absorption
• Prone to uneven or patchy results
• Less responsive to short processing times

These changes are why grey hair may appear coarse, dull, or difficult to dye — even when the same products worked well before.

Why Sensitive Scalps React More as Hair Turns Grey

Scalp sensitivity often increases with age, hormonal changes, or repeated exposure to oxidative dyes.

Common reasons reactions become more noticeable:

• Reduced scalp barrier function
• Cumulative irritation from past colouring
• Slower skin recovery after chemical exposure

When grey hair requires stronger or longer processing, the scalp is exposed for longer — increasing the chance of discomfort, itching, or burning.

Common Triggers in Traditional Hair Colour

Many reactions linked to colouring aren’t caused by “colour” itself, but by specific ingredients or processes.

The most common triggers include:

• PPD (p-phenylenediamine) — a strong dye precursor linked to allergic reactions
• Ammonia — raises the cuticle aggressively, increasing scalp exposure
• Fragrance and alcohol — often overlooked but irritating for sensitive skin

For people with reactive scalps, repeated exposure can turn mild discomfort into ongoing sensitivity.

Gentle Alternatives for Covering Grey Hair

Not all grey coverage relies on the same chemistry.

Lower-stress approaches often include:

• Grey blending instead of full opaque coverage
• No-mix colour systems that reduce oxidation intensity
• Lower-maintenance routines with gradual tonal adjustment

These methods focus on softening contrast rather than forcing full saturation, which can significantly reduce scalp stress while maintaining a natural look.

Choosing the Right Routine for Your Scalp Type

There’s no single “best” solution for grey hair — only better-matched routines.

Consider:

• How reactive your scalp has been in the past
• Whether irritation appears during processing or days later
• If you need full coverage or simply want softer transitions

Patch testing and gradual routines are especially important for sensitive scalps, even with gentler systems.

When to Avoid Colouring — and What to Do Instead

If your scalp shows persistent symptoms such as burning, flaking, or delayed reactions, it may be time to pause colouring altogether.

Alternatives during recovery include:

• Letting grey grow with blended tones
• Focusing on scalp care before colour correction
• Using temporary or low-commitment options

Comfort and scalp health should always come before coverage.

Final Thoughts

Grey hair and sensitive scalps require a different approach — not stronger products, but smarter ones. Understanding how grey hair behaves, what triggers reactions, and which routines reduce stress can make all the difference in achieving results that feel as good as they look.

This article is part of Discovery, Inochroma’s learning hub for people exploring gentler, more informed ways to care for grey hair.

FAQ

Is grey hair more sensitive than pigmented hair?

Grey hair itself isn’t sensitive, but changes in structure and scalp condition often make reactions more noticeable during colouring.

Can I colour grey hair without PPD?

Yes. Many people with sensitive scalps choose PPD-free or no-mix systems to reduce irritation risk.

Why does grey hair resist dye?

A tighter cuticle and reduced melanin make grey hair less receptive to traditional colour penetration.

What should I do if my scalp reacts after colouring?

Stop colouring immediately, avoid re-application, and allow the scalp to recover before trying gentler alternatives.