There are no studies showing its effects on healthy males, but it has been shown to drastically improve testosterone in infertile males (ref 77). It's also packed full of minerals, so is a great superfood nevertheless. I use the Sunfoods brand. Make sure you buy from a quality brand, as there are a lot of poor shilajit products out there, also some have been shown to be high in heavy metals.
Ensure that you get adequate restful sleep each night. Sleeping less than the recommended 6 to 8 hours per night increases stress hormones, which lowers testosterone production. Additionally, learn to manage stress levels in healthy ways to naturally increase testosterone. Hormone replacement therapy may be required for some men with low testosterone levels. Consult your physician about treatment options.
Among my favorite stress management tools is the Emotional Freedom Technique (EFT), a method similar to acupuncture but without the use of needles. EFT is known to eliminate negative behavior and instill a positive mentality. Always bear in mind that your emotional health is strongly linked to your physical health, and you have to pay attention to your negative feelings as much as you do to the foods you eat.