As an AI language model, I can provide general guidance on the use of benzoyl peroxide on the face. However, it's important to note that individual experiences may vary, and it's always best to consult with a dermatologist or skincare professional for personalized advice.

When using benzoyl peroxide, it is typically recommended to start with a lower concentration (2.5% or 5%) and gradually increase if necessary. The duration of time to leave benzoyl peroxide on the face can depend on your skin's tolerance and the specific product instructions. In general, it is recommended to leave benzoyl peroxide on the skin for a short period, typically 5-10 minutes, before rinsing it off.

Leaving benzoyl peroxide on the skin for an extended period may increase the risk of skin irritation, dryness, and redness. If you experience any discomfort or excessive dryness, it's essential to reduce the contact time or discontinue use.

Always follow the instructions provided by the product manufacturer and consider consulting with a dermatologist for personalized advice based on your specific skin type and concerns.