Josh Phillips Online coach on Instagram: "Understanding Bone Density & Why It Declines Women reach their peak bone density between ages 25 and 30, meaning their bones are at their strongest during this time. Around age 35, bone mass begins to gradually decline, and as estrogen levels drop leading up to menopause, that loss accelerates. This increases the risk of osteoporosis, fractures, and weaker bones overall. Genetics accounts for about 80% of your peak bone mass, lifestyle choices still play