Yes, you can use niacinamide and clindamycin at the same time. Niacinamide is a form of vitamin B3 that offers various benefits to the skin, including reducing inflammation, improving the skin barrier function, and regulating oil production. Clindamycin, on the other hand, is an antibiotic that is commonly used topically to treat acne.

Both niacinamide and clindamycin have different mechanisms of action and can complement each other in treating acne. Niacinamide helps to regulate sebum production and reduce inflammation, while clindamycin works by killing acne-causing bacteria.

However, it is always a good idea to consult with a dermatologist or healthcare professional before combining any skincare ingredients or medications. They can provide personalized advice based on your specific skin concerns and medical history. Additionally, they can guide you on the appropriate concentrations and formulations of niacinamide and clindamycin to use for your skin type.