Cyproterone acetate (CPA) is commonly used in gender-affirming care as an anti-androgen medication for transgender women (assigned male at birth) or those with androgen-dependent conditions. While it can be effective in reducing testosterone levels and aiding in feminisation, it’s essential to be aware of potential side effects and risks associated with its use. Here are some unwanted/adverse/side effects of cyproterone acetate:
| Side Effect | Description |
| Liver function abnormalities | Cyproterone acetate may cause liver toxicity, including elevated liver enzymes. Periodic monitoring of liver function through blood tests is recommended during treatment. |
| Depression and mood changes | Some individuals may experience mood swings, depression, or changes in emotional well-being while taking cyproterone acetate. It’s essential to monitor mood changes and consult with a healthcare provider if significant mood disturbances occur. |
| Reduced libido | A decrease in libido (sex drive) can occur as a side effect of cyproterone acetate due to its anti-androgenic effects. |
| Fatigue and lethargy | Some users may experience increased fatigue or feelings of lethargy while taking cyproterone acetate. |
| Osteoporosis | Long-term use of cyproterone acetate can increase the risk of osteoporosis due to decreased bone density. Bone density monitoring and supplementation with calcium and vitamin D may be recommended. |
| Weight changes | Weight gain or weight loss can occur as a side effect of cyproterone acetate treatment, though individual responses may vary. |
| Breast tenderness | Cyproterone acetate may cause breast tenderness or enlargement, which can be a desired effect for transgender women but may cause discomfort in some individuals. |
| Headaches | Headaches, including migraines, have been reported as a side effect of cyproterone acetate use. |
| Decreased fertility | Cyproterone acetate can suppress sperm production and fertility in individuals assigned male at birth. It’s essential to discuss fertility preservation options with a healthcare provider if fertility preservation is desired. |
| Thromboembolic events | While less common, there is a risk of thromboembolic events (such as blood clots) associated with cyproterone acetate use, particularly at higher doses or in individuals with other risk factors for thrombosis. |
| Gynecomastia | In individuals assigned male at birth, cyproterone acetate can cause breast development (gynecomastia), which may be desired but can also cause distress in some cases. |
| Hyperkalemia | Cyproterone acetate can lead to elevated levels of potassium in the blood, which can be dangerous, especially in individuals with kidney problems or those taking medications that affect potassium levels. |