Side Effects of Tylenol for Bodybuilding and Muscles

Many bodybuilders take Tylenol and other painkillers on a regular basis to counteract pain after working out. Bodybuilders need to consider two types of side effects before taking acetaminophen, the active ingredient in Tylenol, or other painkillers. First, scientific studies have shown that nonsteroidal anti-inflammatory drugs, including aspirin, Tylenol, Advil, Motrin and Aleve, can inhibit muscle growth in bodybuilders, exactly the opposite effect that bodybuilders are seeking. Second, anyone who takes Tylenol over a long period of time is risking severe illness.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.


Tylenol is a brand name for acetaminophen, which is a main ingredient in other pain relievers and fever reducers as well. Such pain relievers are effective for minor injuries and fever. But Tylenol should only be used on a regular, long-term basis under a doctor's supervision.

Muscle Growth

A number of studies have examined the effects of Tylenol and other NSAIDS on muscle growth 1. The studies indicate that taking NSAIDS to relieve pain during or after your workout is counterproductive, because they inhibit protein synthesis, which in turn inhibits the growth of muscles. In a 2002 study published in the "American Journal of Physiology Endocrinology and Metabolism," protein synthesis was tested in groups that took acetaminophen, ibuprophen, the main ingredient in Advil and Motrin, or a placebo. The placebo group had a 75 percent higher rate of protein synthesis than the groups taking NSAID painkillers. A 2006 study on rats published in "Medicine & Science in Sports & Exercise" found that injecting ibuprofen directly into muscles resulted in 50 percent less muscle growth.

Tylenol Risks

Even if Tylenol and other NSAIDS painkillers helped grow muscles instead of inhibiting their growth, you should be leery of over-using Tylenol or any other brand of painkiller with acetaminophen. Medline Plus states that acetaminophen is one of the most common causes of poisoning in the world 2. Consuming more than 4,000 mg in a day, the maximum recommended dose, can cause adverse reactions. Taking more than 7,000 mg in a day can result in a severe overdose and cause symptoms such as coma and convulsions. Without rapid treatment, large overdoses of acetaminophen can result in liver failure and death.


A healthy alternative to acetaminophen and other painkillers for muscle soreness may be cherry juice. A study published in the "British Journal of Sports Medicine" in 2006 found that muscle damage and pain after exercise such as weightlifting was significantly lessened by the consumption of fresh cherry juice 3. The control group, which drank a placebo, had a 22-percent muscle loss after exercise compared to a 4-percent loss for those who drank cherry juice. After 96 hours, those drinking cherry juice found muscle strength had improved. In addition, the control group reported more pain for a longer period of time.