Transdermal vs Oral

Systemic HRT is available as oral or transdermal preparations.

Transdermal oestrogen preparations should be used first line in women with risk factors for VTE or stroke. This is because oral oestrogen can increase the risk of clot due to its first pass hepatic metabolism.

NICE says other conditions where the transdermal route may be appropriate include:

• Gastrointestinal disorders where absorption may be affected.
• If an individual is taking a hepatic enzyme inducing medication.
• In individuals with cardiovascular risk factors such as obesity, uncontrolled hypertension or hypertriglyceridaemia.
• A history of migraine or gallbladder disease.
• Lactose sensitivity (most oral preparations contain lactose).
• Troublesome symptoms or adverse effects with oral treatments.