Will testosterone pill work for someone who is 20 years old?

20yo or 35yo?: Low T is uncommon in 20yo. Go see your family doc for evaluation. Regardless of age, we (I) don't recommend prescription testosterone pills for anyone because of risk of liver damage. Given all the other prescription TRT, it's not worth taking excess risk. However, if you're referring to over-the-counter "testosterone boosters", then there's really no data that they work, much less are even safe.