Depilatories literally melt and dissolve hair with strong ingredients like calcium hydroxide and sodium or calcium thioglycolate. There are many reasons why this group of products is not great for everyone. The most compelling one is that they pose the risk of causing serious irritation or (in the extreme case) possible burns to the skin and eyes. It is essential to test the depilatory on your arm first as a precaution against allergic reactions or skin sensitivities. Hair and skin are similar in composition, so chemicals that destroy the hair can also destroy the skin.
Depilatories, much like shaving, remove only the hair on the surface, which means the hair comes back in just a few days. To get the best results from your depilatory, first apply warm to hot (but not too hot) compresses, which help soften the hair and pores (where the hair is growing), allowing the depilatory to be absorbed better. Then apply an extremely thick, generous layer of the depilatory completely over the entire length and base of the hair shaft area and let it stay on for the full recommended time, but no longer than between 4 and 15 minutes, depending on how fine or coarse the hair is. Because depilatories dissolve the hair, applying pressure can help remove more of the shaft. Instead of simply washing the depilatory away, use a washcloth and wipe the cream off, using a firm back-and-forth motion.
Depilatories should never be used for the eyebrows or other areas around the eyes, or on inflamed or broken skin.