Taking high-dose zinc lozenges doesn't really help shorten headaches or fevers when adults have a cold, according to a review of three studies.

Taking high-dose zinc lozenges every day might help adults get over colds faster—cutting how long you're sick by more than a third compared to not taking them.

Taking zinc lozenges with less than 75 mg per day doesn't seem to shorten how long a cold lasts, based on studies comparing them to fake pills. It might only work if you take enough.

Taking high-dose zinc lozenges when you have a cold can cut down how long your muscle aches last by more than half, which is the biggest improvement for cold symptoms like this.

Taking certain zinc lozenges (not the acetate kind) in high daily doses might shorten how long you have a cold by about one-fifth, but different brands or types seem to work differently based on studies.

Taking high-dose zinc lozenges for a cold for up to two weeks is generally safe and well-tolerated, with few side effects, according to studies with nearly 200 people.