How can i effectively treat acne or pimple overnight?

You can't: A cortisone injection can reduce the size of an acne but it may not quite clear over night. You should see your dermatologist for proper evaluation and treatment.

Pimple Info: Pimples occur when glands in our skin get blocked and what they secrete collects and causes pressure.The immediate response is inflammation (red, hot, tender swelling). The body increases blood flow to the injury to bring healing factors and also the veins expand to carry bad stuff away. Gentle cleansing and avoid picking/squeezing lets nature take its course. It usually takes more than overnight.