Can i use a protein powder in shakes while on birth control? will it decrease its effectiveness?

No: It should not change effectiveness, but why not eat your protein as low fat meats, fish and legumes? Most people in developed countries are not protein deficient. Best wishes.

It's fine: Protein powder in no way effects the efficacy of your birth control. It's like wating a steak....It's just protein, not anything that interferes with your medicine. Make sure you drink plenty of water though, if you're doingprotein supplements so you don't overstress your kidneys