July 28, 2014 — Tylenol (acetaminophen) is no more effective than a placebo for treating low-back pain, according to a study published in The Lancet.

The conclusions of the study were based on data from over 1,600 patients in Australia who were split into three groups. Each group was given two boxes.

One group was given a two boxes of 500-mg acetaminophen, one group was given one box of acetaminophen and one box of placebo, and one group was given two boxes of placebo. They were instructed to take six pills from one box and up to two pills from the other box “as needed” every day to treat back pain.

Three months later, researchers found no difference among the groups. The patients on placebos recovered within 16 days on average. Those on acetaminophen got better after 17 days. After 12 weeks, sustained recovery was achieved by 83-85% of patients in all groups. Tylenol also had no significant effect on short-term pain levels, disability, function, sleep quality, or quality of life.

Dr. Christopher Williams, the lead author on the study, questioned the endorsement of Tylenol as a first-line treatment for back pain:

“The results suggest we need to reconsider the universal recommendation to provide paracetamol as a first-line treatment for low-back pain, although understanding why paracetamol works for other pain states but not low-back pain would help direct future treatments.”

Earlier this year, the U.S. Food and Drug Administration (FDA) restricted the dose of acetaminophen in prescription painkillers. The agency found that there was not evidence that doses of acetaminophen higher than 325-mg per pill “provide additional benefit that outweighs the added risks for liver injury.” Click here to read more.