I'm just 21 and feel low t what can i do to boost my testosterone level ?should i take any supplement?

Not likely-evaluate!: It is extremely rare for a 21 yo to have low testosterone. Symptoms of low t are nonspecific. Other imbalances with similar symptoms are much more likely such as low thyroid or adrenal function, depression or heavy metal toxicity. See a doctor for evaluation. You can ask a doctor to test free and total testosterone levels, though your doctor will likely suggest other tests as well.