Hello, Welcome to healthcare magic. Acne at the age of 40 is termed as adult acne. Some factors contributing to this are cosmetics, stress and hormonal imbalance. Please get yourself checked to rule out hormonal imbalance and get treated if any abnormality is present. Do not use cosmetics which have a greasy or creamy base. You could consider oral isotretinoin. This is a drug which needs to be taken strictly under the supervision of a dermatologist as it has some side effects which needs to be monitored. But it gives very good results. You could discuss the same with your treating doctor. Wash your face with a pH balanced face wash, preferably a one containing 1-2% salicylic acid. You may apply a gel containing clindamycin 1% in the morning over pimples and Benzoyl peroxide 2.5% gel at night over pimple prone areas. Avoid creams on your face. Avoid too much oil on your scalp. Diet is important. Avoid milk and milk products like cheese, chocolates, sweets, sugary foods and drinks. Eat a lot of fruits rich in vitamin A Hope this helped. Take care.