Variously called Death Day, Decision day, and a number of other less kind words, D-Day was the day that the Allies began the big push from the coast of France all the way to the heart of Germany, ending WWII.
More importantly when it comes to cystic acne, tea tree oil can be harmful to your skin when applied in high concentrations. Some individuals have reported severe skin irritation and allergic dermatitis after applying too much tea tree oil, or applying the proper dose too frequently.
Oily Skin. You're thinking oil = breakouts. But there's an oil that's a natural bacteria killer and it actually fights breakouts: tea tree oil. You can use it as a spot treatment on acne or use a tea tree oil face wash to treat your entire face. It's gentler than the usual acne treatments of benzoyl peroxide or salicylic acid, so if either of those ingredients have given you dry, flaky skin in the past, it's worth giving tea tree oil a go.