One Plot for Aging (Bones and Muscles)

One Plot for Aging (Bones and Muscles)

Created On
Dec 07 2020
Last Updated
Jan 01 2024

Muscle and bone health peak around the age of twenty-five. That is when the hormone responsible for maintaining them peaks.

This subsequent decline after this peak has been widely studied and is part of the natural aging process. The consensus of several studies is: there is decline in testosterone levels with age and it’s normal.

The Massachusetts Male Aging Study looked at the effect of aging on key hormones in human endocrine system. The plot above from this study shows a decline of approximately 1.2% per year in free testosterone levels. This directly relates to the bioavailable testosterone responsible for maintaining muscle and bone health. The plot is based on data from The Journal of Clinical Endocrinology and Metabolism, 1991.

The male sex hormone is responsible for maintaining muscle and bone health in men. The rate of decline correlates strongly to overall health in men.

Other hormones in the endocrine system also decline with age. However, experts consider testosterone as the most important male hormone to maintain well being and quality of life for men.

Regular exercise, especially weight training, can help maintain the body’s natural decline.

Healthy testosterone levels

The National Academy of Sciences says that apart from aging many other factors can affect testosterone levels. These include high BMI (body weight), smoking, alcohol use, chronic diseases (e.g., diabetes, endocrine disorders), and use of certain medications (e.g., cortisol related medications).

Consider testing if…

The FDA believes more people are checking their testosterone levels than necessary. If you have doubts about your levels, first check the resources available on this site.

Health is very personal. Be informed. A good place to start is the detailed discussion on our page, All About Testosterone and then learn about Testosterone and Aging.

If you consider testing, a simple saliva test is the first step. Testing is easy, inexpensive, reliable, and confidential. An online testosterone test from a CLIA-certified lab can be ordered from the comfort of your home.

One point to note: levels vary through out the day, starting high in the morning and gradually declining during the day. So always collect a sample after 30 minutes of waking up for most accurate results. can help test your hormone levels from the comfort of home. For a full hormone analysis you can order a Male Health Test or a Female Health Test. We also provide individual hormone panels, e.g., a testosterone test kit. Our saliva based kits are reliable, convenient, and do not require any blood sample. Please see the FAQs for more information.