What does using steroids (as in sport) do to your bones?
Steroids in sport appear to stimulate bone formation in the short term, but they disrupt your hormonal balance in a way that can actually damage bones. Especially for young people and with prolonged use, the risks are serious enough to avoid.
Anabolic steroids in principle stimulate bone formation and inhibit bone breakdown. They help maintain the spongy inner bone and increase the hard outer bone. At first glance that sounds beneficial. However, the studies demonstrating this largely used lower doses than athletes actually take in practice, which means the real risks are probably being underestimated.
The danger lies in an indirect pathway. AAS use suppresses the body's own testosterone production and the hormones that control the gonads. This effect can persist for months after stopping. Because both testosterone and oestrogen are needed for healthy bones, that suppression still ends up harming your skeleton. Oestrogen is one of the most powerful protectors of bone in both men and women, and a deficiency of it is the primary cause of osteoporosis after menopause.
Some synthetic steroids cannot be converted into oestrogen. These variants suppress the body's own hormone production without the body receiving any oestrogen in return. How great the resulting damage to the skeleton is has not yet been properly studied, but the concern is real.
For young people there is an additional risk. At the end of puberty, steroids accelerate the closure of the growth plates, the zones in the bone where lengthwise growth takes place. Someone who uses steroids at that stage stops growing earlier and may end up shorter than would otherwise have been the case. This is clinically relevant for adolescents.
As for the long term, the honest answer is: we do not know well enough. Most research ran for too short a time or used doses that were too low. What is clear is this: the hormonal disruption that steroids cause is a proven risk factor for bone problems, and those risks accumulate the longer or the more you use.
This answer is based on multiple review studies by experts who have brought together the available literature on androgens, bone metabolism and steroid use in athletes. The evidence on the direct bone effects of androgens is reasonably solid, but for the specific doses athletes use and the long-term consequences the research is thin and the risks are probably underestimated.
Can statins (cholesterol-lowering medications) affect your bones?
Statins show positive effects on bone in laboratory and animal research, but randomised trials in humans do not confirm this. There is therefore no need to reconsider your cholesterol medication for the sake of your bones, but do not expect any bone protection from it either.
What happens to your bones when you lie in bed for a long time?
Prolonged bed rest demonstrably leads to substantial bone loss, particularly in the hip, spine and heel bone. Recovery takes much longer than the period of bed rest itself, so resuming movement as soon as possible is the best thing you can do.
Do carbonated drinks damage your bones?
Regularly drinking large amounts of sugary carbonated drinks is associated with lower bone density, especially in women and during puberty. Moderate consumption appears less harmful, but it is preferable to replace soft drinks with beverages that support bone development.
Can having too little body fat damage your bones?
Too little fat can damage your bones, but muscle mass and the location of fat matter at least as much. If you have concerns about bone health in combination with low body fat, discuss this with your general practitioner or sports medicine physician.
Is eating plant-based bad for your bones?
Eating strictly vegan is associated with lower bone density, but if you adequately supplement calcium and vitamin D, the elevated fracture risk largely disappears. As a vegan, also pay attention to vitamin B12, and discuss any supplement use with your GP or dietitian.
What does sunlight do for your bones, apart from vitamin D?
Sunlight helps your bones through vitamin D, but a separate bone benefit outside that pathway has not been demonstrated and has not been studied; for your bones, what matters most here is how much vitamin D you produce.