Saponins contained in yam skin or plant alkaloids contained in mucus will make yam allergic and itchy after a few people contact it, so direct contact should be avoided when handling yam.

This product nourishes yin and helps dampness, but it is not suitable for those with excessive dampness, stagnation and excess. And has astringent effect, so it is contraindicated for people suffering from cold, dry stool and gastrointestinal stagnation. Don't eat it raw, pregnant women should eat it carefully, because there are certain toxins in raw yam.