Question: what is the best supplement to increase testosterone?
Answer: D-Aspartic Acid. D-Aspartic acid is a natural amino acid that can boost low testosterone levels. ... 
Vitamin D. Vitamin D is a fat-soluble vitamin produced in the skin when exposed to sunlight. ... 
Tribulus Terrestris. ... 
Fenugreek. ... 
Ginger. ... 
DHEA. ... 
Zinc. ... 
Ashwagandha.