Never Combine Hydroquinone with Benzoyl Peroxide or Resorcinol
Use of hydroquinone with any products containing benzoyl peroxide, hydrogen peroxide, or other peroxides may cause temporary staining of the skin (Drugs.com). This staining is temporary and can typically be removed with soap and water washing, but it’s best to avoid benzoyl peroxide-based acne treatments and oxygen-infusing skin care treatments, which typically contain hydrogen peroxide.
In addition, you also want to avoid using resorcinol with hydroquinone. Ochronosis occurrence in persons with darker skin is a well-documented occurrence with combined use of resorcinol and hydroquinone. Hundreds of ochronosis cases have been documented from using resorcinol/hydroquinone combination treatments in South Africa before 1984 (Journal of Dermatological Treatment, 1997).