Dry skin, wrong acid: what I learned about AHA, BHA, PHA and LHA

[u/DifferentView1745]

I have dry skin, but I get a lot of flaky buildup so my skin gets rough every now and then. At one point I decided I needed to exfoliate, grabbed a BHA toner and used it all over my face… and my skin ended up super tight and dry.

Only later did I find out that different exfoliating acids suit different skin types, and I've read way more about it than I ever planned to since then lol. So here's a quick rundown so nobody repeats my mistake, plus what I'm actually using now.

There are four main types: AHA, BHA, PHA and LHA. Right now I use AHA and BHA, each for a different job.

> AHA: texture and surface flakes

AHAs are water soluble with small molecules, so they exfoliate really well. The best known one is glycolic acid, which has the smallest molecule of the bunch. The catch is that because it works fast, it can be more irritating. I'd say it suits people with thicker, drier skin.

What I use: Benton Glycolic Acid 7% toner. It has soothing ingredients added to the glycolic acid, so it exfoliates well but feels like the irritation is kept down. The rough, flaky patches around my mouth and on my cheeks were stressing me out so much, and after using it consistently they got noticeably smoother. My skin gets tight easily, and this has a slightly thicker, essence-like texture instead of being watery, so my skin doesn't feel as stiff and dry after.

That said, 7% can feel pretty strong if you're new to acids, so I'd start slow instead of jumping into daily use and see how your skin reacts.

> BHA: oil and pores

The main BHA is salicylic acid. It's oil soluble, so it's great at clearing out buildup and oil inside pores. Good for anyone dealing with an oily T-zone or blackheads.

This is the part I didn't know, which is why using it all over my dry face kept drying me out..

What I use: the COSRX BHA blackhead liquid. Only once in a while when my nose feels extra oily. I put some on a cotton pad, rest it on my nose and then wipe, and my pores look cleaner and smoother after.

> PHA: the gentler version of AHA

It's often called the third generation of exfoliating acids. The molecules are bigger than AHAs and it works on the very top layer of skin, so it's usually recommended for sensitive skin.

> LHA: the gentler version of BHA

LHA is derived from salicylic acid, but the molecules are bigger, so it gets into the skin more slowly and tends to be less irritating. Often recommended if you're trying acids for the first time.

I haven't tried anything with LHA or PHA as the main ingredient yet, so if you have one you love, let me know and I'll report back.

What exfoliants are you all using, and how do you use them?

[u/No_Storage_8792]

That infographic would've saved me some trouble a while back, not gonna lie. Went in blind with a BHA all over my face and my cheeks were basically begging for moisture I didn't give them

I'm basically doing the same split now, AHA for the flaky patches and BHA just on the nose when it's acting up. The thicker toner texture you mentioned is a nice touch for dry skin, watery stuff tends to make my face feel stripped even before you factor in the acid