As an expert in skincare ingredients, I can provide some insights on using lactic acid and clindamycin together. Lactic acid is an alpha hydroxy acid (AHA) commonly used in skincare products for its exfoliating and brightening properties. It helps to remove dead skin cells, improve skin texture, and promote cell turnover.

On the other hand, clindamycin is an antibiotic that is often prescribed topically or orally to treat acne. It works by reducing the growth of bacteria on the skin, thereby reducing inflammation and preventing breakouts.

While both lactic acid and clindamycin can be beneficial for acne-prone skin, it's important to exercise caution when using them together. Lactic acid can lower the pH of the skin, which may increase the effectiveness of clindamycin. However, combining the two ingredients can also increase the risk of skin irritation or dryness, especially if you have sensitive skin.

To use lactic acid and clindamycin together, it's best to consult with a dermatologist or skincare professional who can assess your specific skin needs and guide you on the appropriate concentrations and application methods. They can help determine if the combination is suitable for your skin and provide personalized recommendations to minimize any potential side effects.

Remember, it's always important to patch test new products or combinations on a small area of skin before applying them to your entire face, and to follow any instructions or guidelines provided by your healthcare professional.