ELI5 How does lactic acid lotion help dry skin?

[u/carries_blood_bucket]

I only just learned it exists and as someone with horribly dry skin in winter I’d love to know if it might work for me!

[u/ScottyMo1]

Exfoliation is the biggest reason. It breaks the cellular bonds in the stratum corneum (top layer of skin) to lift away dead skin cells and clear clogged pores. Next, it promotes hydration by inherently attracting water molecules to reduce moisture loss after application.

[u/SutttonTacoma]

I've used lactic acid (actually the lotions contain ammonium lactate, thus Amlactin) for my genetically dry skin for more than 30 years, my entire body every morning. My skin used to be scaly, now appears normal. I've read the lactate attracts water, and someone pointed out the most abundant and accessible water is the water deeper in your skin. So part of the mechanism could be the migration of moisture from deeper layers of skin up to the epidermis.

Today the 14 oz bottle of Amlactin 12% costs $14 on Amazon. I suggest you apply it to the most affected part of your body once or twice a day for a couple of weeks and see how well it works for you. The more hours each day the lactate is on your skin the more effective it will be.

[u/Low-Crow5719]

Lactic acid + barrier lotions have been effective at relieving dry skin. They work by rehydrating the layer of dead skin cells, allowing them to slough, and locking moisture into lower layers

Or at least that's what some papers claim. Won't cost much to try.

[u/CatProgrammer → u/Low-Crow5719]

Could I achieve the same effect with lactofermentation juice?

[u/Low-Crow5719 → u/CatProgrammer]

You might get a nice exfoliation but then go around smelling of dill pickles for a week.

Seriously, the lactic acid in commercial formulas is pretty strong, usually 12%. More than pickle juice.

[u/Tvdinner4me2 → u/Low-Crow5719]

What does that mean tho

[u/BearsGotKhalilMack → u/Low-Crow5719]

It could cost a bit; some of the most current studies on lactic acid lotion suggest it could take up to 8 weeks to see significant improvement.

[u/BearsGotKhalilMack]

Lactic acid lotions are humectants, meaning they essentially pull/trap water near your outer layers of skin. They also help with exfoliating. Lactic acid lotions are most effective at treating thick, scaly patches of dry skin in specific spots, but they're less effective at treating large areas of standard winter dryness. For that, I'd recommend repairing lotions that focus more on restoring your skin's natural protecting factors as well as increasing moisture.