"Previous studies have suggested that smoked cannabis increases pain. This is the first study using a dose-response method that suggests smoked cannabis has a therapeutic window with moderate doses decreasing pain and high doses increasing pain," said lead investigator Dr. Mark Wallace of the University of California, San Diego, according to Reuters.

The study analyzed 15 healthy volunteers who smoked low, medium and high doses of cannabis. The participants were also injected with capsaicin, the spicy substance found in chili peppers in order to induce the pain.

No dose of smoked cannabis had any effect at 5 minutes after the volunteers were injected. However, the pain was significantly reduced 45 minutes after lighting up a moderate dose of cannabis. Subjects felt higher when smoking a high dose and their pain was highly increased. Those smoking a low dose didn’t know any effects.

Although the study has significant results, researchers said that no one should draw any conclusion on the pain-relieving efficacy of smoked cannabis. They concluded that further study is needed, so researchers can be sure they can apply this theory.

The study is published in the November issue of the journal Anesthesiology.