Which has fewer side effects, anastrozole or letrozole?

Generally speaking, there is no absolute claim that anastrozole has fewer side effects than letrozole. Both drugs have similar types of side effects, but individual responses may vary, so the choice should be based on specific circumstances. If in doubt, it is recommended to consult a healthcare provider in advance. Detailed analysis is as follows:

In terms of common side effects, both medications may cause symptoms such as hot flashes, fatigue, and joint pain. However, individuals may differ in their sensitivity to each drug. For example, some users report milder gastrointestinal discomfort with anastrozole, while joint pain may be more pronounced with letrozole. Others have noted that anastrozole may have a slightly smaller impact on blood lipid levels, while letrozole may be associated with a relatively lower incidence of muscle aches. These differences are related to variations in drug metabolism pathways and individual tolerance.

Regarding special side effects, both drugs may affect bone density. Clinical observations suggest that letrozole may carry a slightly higher risk of osteoporosis in some individuals compared to anastrozole. However, this difference is not definitive and must be evaluated in conjunction with factors such as age and baseline health status. Additionally, both drugs have a similar potential impact on liver function, requiring regular monitoring. The likelihood of individual patients developing abnormal liver enzymes may vary.

When choosing between these two medications, patients should inform their doctor about their medical history, previous medication use, and expectations regarding side effect tolerance. After starting treatment, they should closely monitor their body's response and promptly seek follow-up if significant adverse reactions occur. Treatment plans should be adjusted by a physician—patients must not switch medications on their own.