Bazedoxifene
A third-generation indole SERM used for osteoporosis, often combined with conjugated oestrogens. It antagonises oestrogen in breast and uterus while acting as an agonist on bone, and is discussed in PED circles for anti-estrogenic bone protection.
01 Overview
Bazedoxifene (Conbriza/Duavee, the latter combined with conjugated equine oestrogens) is an indole-based SERM approved for the prevention and treatment of postmenopausal osteoporosis. It preserves bone mineral density while blocking oestrogen stimulation of endometrial and breast tissue.
It is not a mainstream PCT agent — its gonadotropin-stimulating profile in men is poorly characterised — but its bone-sparing, breast-antagonist profile occasionally attracts interest as an alternative to aromatase inhibitors that spare bone.
02 Mechanism
Indole SERM: agonist at oestrogen receptors in bone, antagonist in breast and endometrium, producing anti-resorptive effects without endometrial proliferation.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Osteoporosis | 20 mg/day | Oral | Licensed dose. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Bone mineral density preservationAgonist action on bone reduces resorption and fracture incidence. | Reduced vertebral fracture risk | Clinical | |
| Endometrial protectionAntagonises uterine oestrogen receptors, allowing safe pairing with oestrogens. | No endometrial hyperplasia | Clinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Muscle spasms / leg crampsFrequently reported labelled effect. | Mild | Common | Clinical | |
| Venous thromboembolismSERM class risk of deep vein thrombosis and pulmonary embolism. | Severe | Rare | Clinical |