When you are suffering from either a headache, a stiff back or joint pain, or sore muscles you probably reach for the nearest bottle of acetaminophen, ibuprofen, or aspirin, take a tablet or two according to the instructions on the label, and hope that the pain subsides fairly quickly.

A new study published by the United Kingdom’s Oxford University comparing the effectiveness of common pain medications suggests that, depending on the pain medication chosen, you might not have much to hope for in terms of pain relief. The study found that only around 33% of individuals who take a single dose of acetaminophen (600 mg) or aspirin (1,000 mg) experience what they’d classify as “good relief” from their acute pain. In the context of the study, “good relief” was defined as a perceived 50% reduction in pain that lasted for between 4 and 6 hours.

The British study that was performed aggregated the data of over 350 separate trials comprising a total of 45,000 participants. Nearly 50 different drugs and specific drug combinations were tested for their efficacy in relieving acute pain at various doses.

Huge Discrepancies in Effectiveness

According to the study’s results, one of the least effective pain drugs was codeine. A single 60 mg dose of this drug led to good pain relief for only 14% of participants. On the opposite end of the relief spectrum were etoricoxib (120 mg) and an ibuprofen/acetaminophen combination (200 mg and 500 mg of each, respectively). These drugs and drug combos resulted in good relief for 70% of participants. The results for certain drugs, such as arthritis pain meds meloxicam and nabumetone, were inconclusive.

The researchers were quick to point out that no drug resulted in good relief for all patients, and the majority of the drugs were only effective for less than half of the participants. They also emphasized the fact that a drug’s ability to relieve your pain will depend in part on the type of pain you’re experiencing, and that a drug that provides good relief for one individual may not provide any help for another, even one who is experiencing the exact same type of pain. Still, they stressed that consumers would have better luck with a pain drug that helped 70% of participants than one that only helped 14%.

The Nature of the Studies

Most of the trials involved in the overall study were conducted in a very simple manner: participants were given either placebos or certain pain medications to treat pain resulting from surgery, in many cases the removal of their wisdom teeth.

In order to gauge the effectiveness of each drug, the researchers looked at how many people would need to consume a particular drug in order for one of the individuals to experience good relief. The number for codeine, for example, was 12 individuals, while the number for ibuprofen (400 mg) was much lower at 2.5.

Some of the drugs truly excelled in that they were able to provide good relief for more than 8 hours. These drugs included celecoxib (400mg), acetaminophen/oxycodone (650 mg and 10 mg, respectively), and diflunisal (500 mg). Diflunisal and celecoxib are better known by some of their marketing names, including Dolobid and Celebrex.

Comparing Common Pain Medications: All or Nothing

One of the study’s lead researchers noted that for many individuals, a drug will either provide all of the relief they’re seeking or none at all. He said that if you receive a pain prescription from your doctor and find that it doesn’t work after the first couple of instructed doses, you should immediately ask your doctor to suggest an alternative.

Before taking any medication for acute pain, it’s important to note that all pain meds have side effects, some of which can be dangerous. Always talk to your doctor before taking a medication with which your body is unaccustomed, and read the labeling carefully to determine the side effects, usage instructions, drug combination warnings and proper dosages. This advice most certainly applies to over-the-counter medications as well as the prescription ones suggested by your doctor.