How should I counsel a patient on the potential side effects of the combined pill, patch, and ring?

Combined Oral Contraceptive Pill (COC): Counsel patients that the COC can cause side effects such as mood changes, headaches, pelvic pain, nausea, breast discomfort, and unscheduled bleeding. Mood, headache, and pelvic pain may improve with tailored regimens such as extended use. Fertility typically returns quickly after stopping the pill. Emphasise the importance of taking the pill regularly at the same time each day to maintain efficacy.

Contraceptive Patch: Inform patients that side effects are similar to the COC but may include more breast discomfort, dysmenorrhoea, nausea, and vomiting. The patch can cause minor skin irritation at the application site, which can be managed by changing the patch location. The patch may be less effective in women weighing over 90 kg and can become detached, reducing efficacy. There is some evidence that the risk of venous thromboembolism (VTE) may be higher with the patch compared to COCs. Return to fertility may be delayed by a few months after stopping the patch.

Vaginal Ring: Side effects are similar to the COC but may include vaginal irritation and discharge in 5-6% of users. Users report less nausea, acne, irritability, and depression compared to COC users. There is some evidence that VTE risk may be higher with the ring than with COCs. Some women may not experience a withdrawal bleed during the ring-free week, which is usually not a sign of pregnancy if the ring has been used correctly. Liver enzyme-inducing drugs can reduce the efficacy of all these combined hormonal methods, so patients should be counselled accordingly.