Several supplements and herbal extracts have been studied for their potential to increase testosterone levels. Here are some of the notable ones:

1. Vitamin D: There is evidence to suggest that vitamin D supplementation can increase testosterone levels in men, particularly in those who are deficient in vitamin D¹.
2. Zinc: Zinc is an essential mineral linked with testosterone synthesis. Some studies have shown that zinc supplementation can help increase testosterone levels in men with zinc deficiency².
3. Fenugreek: Fenugreek seed extracts have been found to have a positive effect on testosterone concentrations. It is thought to work by reducing the enzymes that break down testosterone³.
4. Ashwagandha: Ashwagandha root extract has also shown potential in increasing testosterone levels, particularly in stressed individuals³.
5. Magnesium: Like zinc, magnesium is involved in many biochemical reactions in the body, including those that influence testosterone production. Supplementation may help increase testosterone levels in men with magnesium deficiency².

However, it's important to note that the efficacy of these supplements can vary, and many over-the-counter testosterone-boosting supplements may not live up to their claims. Always consult with a healthcare provider before starting any new supplement regimen.

Footnotes

1. S Pilz, "Effect of vitamin D supplementation on testosterone levels in men," PubMed, 2010. ↩

2. Chase G Clemesha, "‘Testosterone Boosting’ Supplements Composition and Claims Are not Supported by the Academic Literature," PubMed, 2019. ↩ ↩²

3. Stephen J Smith, "Examining the Effects of Herbs on Testosterone Concentrations in Men: A Systematic Review," NCBI, 2020. ↩ ↩²