PHA (Polyhydroxy Acids): The Gentlest Exfoliant Guide
PHAs are the gentlest of the hydroxy acids — safe for sensitive skin, rosacea, and ultra-reactive types. Here's the honest guide with top products.
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PHAs (polyhydroxy acids) are the largest-molecule, gentlest hydroxy acids. Common PHAs: gluconolactone, lactobionic acid, galactose. Best for: sensitive/reactive skin, rosacea, post-procedure maintenance, ultra-gentle exfoliation. Top picks: Naturium Alpha-Arbutin Serum w/ PHA, Skin Actives PHA Booster, Exuviance PHA+ Series. Gentler than AHA/BHA with slower results. Pregnancy-safe.
PHAs are the newest category of hydroxy acids — gentler than AHAs and BHAs. Here’s what they actually do.
What PHAs are
PHAs (polyhydroxy acids): gluconolactone, lactobionic acid, galactose. Molecular size 3-5x larger than glycolic acid, too large to penetrate deeply. Effect: surface-level gentle exfoliation without irritation. Also provides humectant (moisturizing) function. Best-tolerated hydroxy acid category for sensitive skin types.
PHA compounds:
- Gluconolactone (most common in skincare)
- Lactobionic acid (largest, gentlest)
- Galactose (specific uses)
- Maltobionic acid (newer)
PHA properties:
- Largest molecular size among hydroxy acids
- Gentle surface exfoliation
- Moisturizing effect
- Low irritation potential
How PHAs compare to AHA/BHA
PHA vs AHA: AHAs smaller, penetrate deeper, stronger exfoliation, more irritation potential. PHAs larger, surface-only, gentle, barely any irritation. PHA vs BHA: BHA penetrates pores (oil-soluble), addresses acne specifically. PHAs water-soluble, surface-level, better for reactive skin. PHAs complement rather than replace — many use PHA daily + stronger AHA/BHA weekly.
Comparison:
- PHA vs glycolic (AHA): PHA larger, gentler, slower results
- PHA vs salicylic (BHA): PHA water-soluble, surface-level; BHA oil-soluble, pore-penetrating
- PHA vs mandelic (AHA): both gentle, PHAs slightly gentler still
Top PHA products
Naturium
Alpha-Arbutin Serum 2%
Arbutin + gluconolactone (PHA).
Best for: Pigmentation + gentle exfoliation
Exuviance
PHA+ Clarifying Toner
Multi-PHA daily toner.
Best for: Daily gentle exfoliation
The Inkey List
PHA Toner
Budget PHA option.
Best for: Affordable PHA entry
Skin Actives
PHA Booster
Pure PHA additive for serum/moisturizer.
Best for: Adding PHA to existing products
When PHAs win over AHA/BHA
PHAs better than AHA/BHA for: rosacea-prone skin, sensitive/reactive skin, post-procedure maintenance, pregnancy (gentle enough), first-time acid users, those who react to glycolic/salicylic. AHA/BHA still better for: thick skin, stubborn acne, severe texture, pigmentation work where penetration matters.
PHAs win for:
- Rosacea-prone skin
- Sensitive/reactive skin
- Post-procedure maintenance
- Pregnancy (gentle enough)
- First-time acid users
- Glycolic-intolerant
AHA/BHA still better for:
- Thick skin
- Stubborn acne
- Aggressive exfoliation needs
- Deep pigmentation
Typical concentrations
PHA concentrations: Daily use: 3-6% gluconolactone. Stronger (weekly): 7-10% PHA products. In-office (medium): 10-20% PHA peels. Much higher concentrations tolerable than AHAs — PHA 10% produces similar irritation to glycolic 5%. Useful for sensitive skin where glycolic is overwhelming.
Concentration guide:
- Daily: 3-6% gluconolactone
- Weekly stronger: 7-10% PHA
- Professional: 10-20% PHA peels
Routine integration
- Daily: PHA toner or serum
- Combine with: vitamin C, peptides, hyaluronic acid
- Space from: retinol (use alternate nights)
- During pregnancy: generally safe, check with OB
Premium Beauty
Gentle exfoliation premium picks
Premium options for reactive/sensitive skin.
SkinMedica
$295TNS Advanced+ Serum
Dual-chamber growth factor + peptide serum. Actually worth the splurge.
Buy on Amazon →SkinCeuticals
$182C E Ferulic Vitamin C Serum
15% L-ascorbic + 1% vitamin E + 0.5% ferulic. The gold standard.
Buy on Amazon →SkinCeuticals
$182Phloretin CF Antioxidant Serum
For oilier skin — phloretin + vitamin C + ferulic acid combo.
Buy on Amazon →Augustinus Bader
$290The Cream
TFC8 tech. The one celebrities keep talking about.
Buy on Amazon →EltaMD
$41UV Clear Broad-Spectrum SPF 46
The derm favorite. Zinc + niacinamide, no white cast.
Buy on Amazon →Supergoop!
$38Unseen Sunscreen SPF 40
Goes on like a primer. Zero white cast, zero scent.
Buy on Amazon →Frequently asked
PHA vs BHA for pores? +
BHA is better for pore-level congestion (oil-soluble, penetrates pores). PHA is better for surface-level dullness and reactive skin.
Can I use PHA daily? +
Yes. PHAs are gentle enough for daily use even in sensitive skin. Start every other day for 2 weeks, then daily if tolerated.
Does PHA replace glycolic acid? +
Not for all uses. PHA is gentler alternative for sensitive skin; glycolic is stronger for thick skin. Different tools for different needs.
Is PHA pregnancy safe? +
Generally yes. Gentler than AHA/BHA. Not fully studied in pregnancy but lower concentration + gentle action makes many OBs approve.
Which PHA is best? +
Gluconolactone is most researched and widely available. Lactobionic acid is slightly gentler still. Either works.
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SkinMedica
$295TNS Advanced+ Serum
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$182C E Ferulic Vitamin C Serum
15% L-ascorbic + 1% vitamin E + 0.5% ferulic. The gold standard.
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$182Phloretin CF Antioxidant Serum
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Buy on Amazon →Augustinus Bader
$290The Cream
TFC8 tech. The one celebrities keep talking about.
Buy on Amazon →EltaMD
$41UV Clear Broad-Spectrum SPF 46
The derm favorite. Zinc + niacinamide, no white cast.
Buy on Amazon →Supergoop!
$38Unseen Sunscreen SPF 40
Goes on like a primer. Zero white cast, zero scent.
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