Patch effectiveness decreases in women weighing more than which weight threshold?

• A. More than 60 kg
• B. More than 90 kg
• C. More than 120 kg
• D. No weight effect

Answer: (B)

Weight can affect how well the transdermal contraceptive patch works because it delivers a fixed hormone dose through the skin and relies on adequate systemic exposure to suppress ovulation. In individuals with higher body weight, the larger volume of distribution can lead to lower circulating hormone levels, which may reduce ovulation suppression and increase the chance of pregnancy. Clinical data show a notable drop in patch effectiveness in women weighing more than about 90 kilograms, making this the weight threshold where efficacy begins to decline. For lighter individuals, efficacy remains high, and the weight-related drop is not observed. So, the most accurate threshold where patch effectiveness decreases is more than 90 kg.