What it's normally used for
Niacin has a bunch of uses on the body, in the digestive system, skin, and nervous system.
Niacin helps the body turn fat, carbohydrates, and proteins into energy. It also plays a role in gland and liver function.
Niacin is also used for circulation problems, treating migraine headaches, and dizziness, and helps reduce diarrhea associated with cholera. It can also lower cholesterol and triglycerides in the blood. The Mayo Clinic reported that niacin can raise HDL (good) cholesterol by more than 30%.
What it does for Lucid Dreaming
Niacin can generate vivid dreams and give you better dream recall.
My own results
I take Niacin before bed and I remember more of the dream, where it seems like it's a longer dream, and I get a nice flush. (Crush it and take on empty stomach for a bigger flush.)