Goji Side Effects
There are currently no known side effects of goji, but this does not mean that side effects are not possible. Taking goji in combination with the "blood thinner" warfarin may increase the risk of bleeding, but this may be a drug interaction rather than a true side effect. If you develop any possible side effects while taking goji, notify your healthcare provider.
Goji is a shrub with edible berries that are often used in health foods and drinks. The bark is also used in dietary supplements. At this time, there are no known goji side effects. However, this does not guarantee that the product does not cause side effects; it simply means that no side effects have been reported, either in clinical studies or in case reports (case reports are individual reports from healthcare providers about side effects seen in their patients). There is a good chance that the lack of reported side effects simply reflects a lack of studies large enough to find side effects; it probably does not indicate that goji really is free of side effects.
There have been reports that taking goji in combination with the "blood thinner" warfarin (Coumadin®, Jantoven®) may increase the risk of bleeding, but similar problems have not been reported in people not taking warfarin. There is evidence that this problem is a drug interaction caused by changes in the way the body handles warfarin, not a true side effect. In other words, taking goji alone would not be expected to increase your risk of bleeding.
If goji really lowers blood pressure and blood sugar (as is often claimed), it would be reasonable to expect that goji could cause dangerously low blood pressure (hypotension) or dangerously low blood sugar (hypoglycemia), although these problems have not been reported with goji.