нет,я не предлагаю наносить гель алоэ-вера перед третиноином,вместо него лучше за полчаса до третиноина протирать лицо балансирующим тоником. Кстати,даже после умывания водой нормальный pH кожи восставливается в течении часа,а после мыла еще дольше.
The acid mantle, the combination of sebum (oil) and perspiration, on the skin's surface protects the skin and renders the skin less vulnerable to damage. It also protects from attack by environmental factors such as the sun and wind and leaves it less prone to dehydration. Normal skin pH is somewhat acidic and in the range of 4.2. to 5.6. It varies from one part of the body to another and, in general, the pH of a man's skin is lower (more acidic) than a woman's. The acid mantle inhibits the growth of foreign bacteria and fungi causing the skin to remain healthier and have fewer blemishes.
Acne, allergies and other skin problems become more severe when the skin become more alkaline.