Unfortunately most patients never have their levels checked. Doctors are too busy checking cholesterol and doing checkboxes for government and insurance bureaucrats to add another thing to their plate. Combine that burden with an 8 minute, if you're lucky, visit and you can see why most patients go without screening for hormone deficiency.

Normal levels and optimal levels for men and women differ greatly, but both can benefit from supplementation when low. Someone may have a "normal" level but still have symptoms of low testosterone. That's why we look for optimal levels. Generally women who have symptoms and have total testosterone below 20 ng/dL may benefit from supplementation. For men with symptoms and levels below 500 ng/dL of total testosterone should consider testosterone replacement therapy (TRT).

So what are symptoms of low testosterone? Mood swings, low libido, low energy, muscle and joint aches, fat gain, and muscle loss are major ones. For men, ED is a problem as well. So if you have any of these symptoms you should consider getting your testosterone checked. If you decide to go for TRT, there a variety of ways to do it. Shots are popular because they are easy to do and you can change your dose easily. Shots are only available for men though. For women, topical creams are a good option. Both men and women can have pellets placed in the subcutaneous tissue. They last for 3-6 months depending on the patient.

Related

Why Are Testosterone Levels Decreasing?
Types of Testosterone Replacement Therapies