Tribulus terrestris is a fruit-producing Mediterranean plant that's covered with spines. It is also called puncture vine.
People use the fruit, leaf, or root of the tribulus plant as medicine. Some formulations also include other ingredients.
A study in men also suggests that glucosamine sulfate may help a person bend and flex the knee better after a sudden knee injury.
Optimal doses of glucosamine sulfate have not been established. Supplement ingredients and quality may vary widely from maker to maker. This makes it hard to establish a standard dose.
The dose used in many studies to treat knee osteoarthritis was 500 milligrams, taken three times a day.
There are different forms of glucosamine. Check the supplement's ingredients. Some may contain glucosamine sulfate. Other supplements may have glucosamine hydrochloride or another type. Most studies have used glucosamine sulfate.
Glucosamine is sometimes found in skin creams used to treat arthritis pain. There is no proof that glucosamine can move through your skin. Scientists think the pain relief may be due to other ingredients in the cream.
Studies done in a laboratory dish hint that glucosamine sulfate may help fight HIV, the virus that causes AIDS. Much more comprehensive research is needed before scientists can say whether or not this supplement could be helpful for those with the virus.