When it comes to acids, clients usually fall into two camps: excitement (“I’ll buy everything with AHAs!”) or fear (“I’ll burn my face off!”). As always, the truth lies somewhere in between. Acids are powerful tools, but the key to safe and effective home use is understanding both skin type and Fitzpatrick phototype.
A bit of science
Acids act as “gentle disruptors”: they dissolve intercellular bonds, speed up skin renewal, regulate sebum, and lighten pigmentation. But they can also cause irritation, photosensitivity, and post-inflammatory hyperpigmentation (PIH) — especially in patients with higher phototypes.
Fitzpatrick phototypes and acid choices
Phototype I–II (very fair and fair skin)
These clients often struggle with sensitivity and redness. Best options:
• Mandelic acid — slow and gentle.
• Lactic acid — hydrates while brightening.
• PHA (gluconolactone) — excellent for skin prone to couperose.
Phototype III–IV (medium, olive, Asian skin)
More resilient, but prone to pigmentation. Strategies focus on PIH control:
• Azelaic acid — reduces inflammation and regulates melanin.
• Glycolic acid — allowed in low concentrations (up to 10%) for home use.
• Salicylic acid — perfect for acne and seborrhea.
Phototype V–VI (dark, Middle Eastern, African skin)
The main risk here is PIH. Even minor irritation can leave lasting marks. So the approach is minimal aggression:
• Azelaic acid — gentle, effective for acne and pigmentation.
• Lactic acid — helps even tone.
• PHA — safe choice for regular mild exfoliation.
Glycolic acid and TCA are off-limits for home care; leave them for clinical use under experienced professionals.
How to explain this to clients
The key message: acids aren’t magic, they’re tools. For fair skin, the risk is irritation; for dark skin, the risk is pigmentation. That’s why home acids must come in low concentrations, and SPF is non-negotiable.
Home acid rules
• Start 1–2 times per week, then increase gradually.
• Never combine multiple aggressive actives at once (like AHA + retinol + high-strength vitamin C).
• Always pair acids with hydrating and barrier-restoring products.
• Teach clients that mild tingling is normal, but burning or prolonged redness means stop.
Conclusion
Acids are neither enemies nor miracle workers. Think of them like a surgeon’s scalpel: it all depends on how and where they’re used. For clients, the main guide should not be TikTok advice, but their phototype — and a professional’s recommendation.
✨ In the Open Beauty Hub community, we discuss protocols for acids, share research, and help professionals explain to clients that acid-based skincare can be both safe and effective when done wisely.