AHA vs BHA vs PHA: Which Acid Suits You in Pakistan?

Chemical exfoliants fall into three families. Alpha hydroxy acids such as glycolic and lactic acid work on the skin surface, beta hydroxy acid, which means salicylic acid, is oil-soluble and works inside pores, and polyhydroxy acids such as gluconolactone are gentler cousins of the alpha group. Choosing between them depends on your skin type, your concern and how well your barrier tolerates acids. This guide compares them and explains how to start safely in Pakistan’s climate.

Key takeaways

AHAs (glycolic, lactic, mandelic) work on the surface and suit dull, rough or uneven skin
BHA (salicylic acid) is oil-soluble and suits oily, clogged, breakout-prone skin
PHAs are larger molecules that tend to be gentler, and may suit sensitive skin
Start slowly, use sunscreen daily and do not stack several acids at once

What are AHAs, BHAs and PHAs?

Hydroxy acids loosen the bonds between dead cells on the skin surface so that they shed more easily. Alpha hydroxy acids are water-soluble and include glycolic acid from sugar cane, lactic acid, mandelic acid and citric acid. The FDA describes alpha hydroxy acids as ingredients used in cosmetics to improve the appearance of skin, and notes that they can increase sensitivity to the sun. Beta hydroxy acid is a name for salicylic acid, which is oil-soluble, so it can enter the oily environment inside pores. Polyhydroxy acids, such as gluconolactone and lactobionic acid, are larger molecules that penetrate more slowly, and a review of polyhydroxy acids describes them as having exfoliating and moisturizing properties with good tolerability.

All three families thin the surface layer of dead cells, so all three raise the importance of daily sunscreen. None replaces moisturizer.

Family	Examples	Solubility	Works mainly on	Typical feel
AHA	Glycolic, lactic, mandelic	Water	Skin surface	Can sting at higher strength
BHA	Salicylic acid	Oil	Surface and inside pores	Often feels light, can dry
PHA	Gluconolactone, lactobionic acid	Water	Skin surface, slow penetration	Usually gentle
Enzyme exfoliants	Fruit enzymes	Water	Surface	Mild, variable

Which acid suits which skin?

The choice follows your skin type and concern rather than a ranking. For oily skin with blackheads and small bumps, salicylic acid is the logical first choice because it works within oily pores. For dull, rough or sun-damaged skin, glycolic or lactic acid is commonly used, and lactic acid is milder than glycolic acid because its molecule is larger and it attracts water. For sensitive, dry or reactive skin, a PHA or a low-strength lactic acid may be better tolerated. For dark marks, exfoliation can help products penetrate and support fading, but it should never replace sunscreen. A review of glycolic acid peels discusses their uses and limits, which shows that stronger treatments belong with trained professionals.

See glycolic acid vs salicylic acid and lactic acid for oily skin for closer comparisons.

Skin or concern	First choice	Second choice	Avoid at the start
Oily, blackheads	Salicylic acid	Lactic acid	Strong glycolic
Dull, rough texture	Lactic or glycolic acid	PHA	High-strength peels at home
Sensitive or dry	PHA or low lactic acid	Rinse-off salicylic acid	Frequent glycolic
Acne with inflamed spots	Salicylic acid	Azelaic acid (separate product)	Harsh scrubs
Uneven tone	Lactic or glycolic acid	Mandelic acid	Daily strong acids
Using retinoids	Alternate nights or skip	Ask your dermatologist	Stacking acids

How do you start and how often?

Begin with a low strength, once or twice a week in the evening, on clean, dry skin, and wait for the skin to feel normal before increasing. Apply a moisturizer afterwards. If your skin stays comfortable for two to three weeks, add another night. Do not use an acid every night unless your dermatologist advises. Skip the acid on days when the skin is sunburnt, scratched, or irritated, and avoid applying near the eyes. Signs of too much include stinging, tightness, peeling and shine without oil; see over-exfoliation signs and repair.

Never combine several exfoliating products in the same session. Face scrubs, acid toners, peel pads and retinoids all add up.

Start once or twice a week at a low strength
Apply at night on dry skin
Moisturize afterwards
Wear sunscreen every morning
Do not stack acids, scrubs and retinoids
Stop if the skin stings, peels or looks shiny and tight

What about sun, heat and Pakistan’s climate?

In hot, sunny weather, exfoliated skin burns more easily and marks more readily, particularly in medium to deep skin tones. Use broad-spectrum sunscreen every morning and reapply when outdoors. In the heat of summer, reduce the frequency of acids, and in very dry winter air, pair them with richer moisturizer. If you travel, pause exfoliating acids for a few days before and during strong sun exposure.

What about acne, purging and pigmentation?

Acids can help with clogged pores and rough texture, but they are one tool among several. A Cochrane review of topical treatments for acne, covering azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acids, described the clinical benefit of these treatments as unclear and found that the evidence for several of them was uncertain, which is a reminder that acids support rather than replace proven acne care. Guidelines of care for acne management give dermatologists’ recommendations for established treatments. If you have inflamed or scarring acne, see a dermatologist. Some people notice more spots in the first weeks of a new acid; see skin purging vs breakout.

For pigmentation, acids may speed up the shedding of pigmented cells, but they can also irritate and cause post-inflammatory marks. Use low strengths and patience.

What should you not combine?

Avoid using several exfoliating acids together, and avoid combining acids with retinoids on the same night unless a dermatologist has advised it. Benzoyl peroxide and acids together can be harsh. Vitamin C serums at low pH can add to irritation for some people. When in doubt, alternate nights and keep the routine short. Our guide on retinol and salicylic acid on the same night explains how to think about combinations.

If you want an acne-focused serum, see the Acne & Oil Control Serum, which lists salicylic acid and niacinamide among its ingredients. Patch test first and start slowly.

Combination	Risk	Better approach
AHA plus BHA same night	Over-exfoliation	Alternate nights
Acid plus retinoid same night	Irritation	Alternate nights or ask a doctor
Acid plus scrub	Barrier damage	Choose one
Acid plus benzoyl peroxide	Dryness, peeling	Use at different times
Acid plus vitamin C	Stinging for some	Test separately

When should you see a doctor?

See a doctor if you get burning, blistering, swelling, spreading rash or dark marks after using an acid, or if acne is inflamed, painful or leaving scars. Stop the acid and use a plain moisturizer in the meantime.

How do you know an acid is working and not harming?

A product that is working usually leaves the skin smoother and a little brighter within a few weeks, with no lasting redness. Mild tingling for a minute after application can be normal for some acids, but burning that lingers, redness that lasts into the next day, flaking, a shiny tight look or sudden breakouts mean that you are doing too much. If this happens, stop all exfoliants and actives, use a plain moisturizer and sunscreen for one to two weeks and then restart at half the frequency. Keep a note of the products and nights you used, since it is easy to forget that a toner, a wash and a serum all contain acids.

Remember that visible improvement takes time. Judge a new acid over six to eight weeks, not a few days, and avoid the temptation to use it more often to hurry the results.

Frequently asked questions

What is the difference between AHA and BHA?

AHAs are water-soluble and work on the surface, while BHA, which is salicylic acid, is oil-soluble and works inside pores.

Which acid is best for oily skin?

Salicylic acid is commonly chosen for oily, clogged skin, with lactic acid as an alternative.

Which acid is gentlest?

PHAs and lactic acid are generally better tolerated than glycolic acid.

How often should I use an exfoliating acid?

Start once or twice a week, and increase slowly only if your skin stays comfortable.

Can I use AHA and BHA together?

It is better to alternate nights, since using them together can over-exfoliate.

Do acids make skin sensitive to the sun?

Yes. Use sunscreen every morning.

Can I use acids with retinol?

Use them on different nights, or ask a dermatologist.

When should I see a dermatologist?

If you get burning, blistering, spreading rash or have inflamed, scarring acne.

Sources

Edison BL et al.. A polyhydroxy acid skin care regimen provides antiaging effects comparable to an alpha-hydroxyacid regimen. Cutis. 2004. PubMed 15002657
Sharad J. Glycolic acid peel therapy – a current review. Clin Cosmet Investig Dermatol. 2013. PubMed 24399880
Liu H et al.. Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha-hydroxy acid) for acne. Cochrane Database Syst Rev. 2020. PubMed 32356369
US Food and Drug Administration. Alpha hydroxy acids

A gentle reminder

Skincare helps the look and feel of your skin; it does not treat medical conditions. Patch test any new product behind the ear or on the inner arm first, and introduce one new active at a time. If you are pregnant or breastfeeding, or you have a skin condition such as eczema, ask your doctor before adding active ingredients. See our FAQ for more, or build your own routine.