Ipriflavone

Snapshot

Indications	Contraindications
Postmenopausal bone loss^{1, 2} Osteopenia or osteoporosis³ Established osteoporosis⁴ Hypogonadism-induced bone loss⁵	Soy allergy⁶ Pregnancy or nursing⁶

Ipriflavone is a synthetic derivative of naturally occurring soy isoflavones that restrains bone turnover by inhibiting bone resorption and supporting osteoblast function⁷. It is taken to slow bone loss, chiefly in postmenopausal women with low bone mass, usually alongside calcium^{1, 2}. Related uses are established osteoporosis in older women and bone loss during medically induced hypogonadism.

The evidence is split. A 2020 meta-analysis of randomized trials found greater lumbar spine bone density than placebo in postmenopausal women with osteopenia or osteoporosis³. A 2001 four-year randomized trial found no prevention of bone loss and no effect on bone turnover markers⁸. Earlier two-year trials reported maintained bone density against placebo loss^{9, 10}. In five healthy men, a 2021 study found ipriflavone altered urinary steroid profiles and raised luteinizing hormone; no larger trial has replicated it. Products listing ipriflavone number over 200 in the United States label database, sold as capsules and tablets; see Form comparison.

The most consequential caution is lymphocytopenia: the four-year trial found a subclinical fall in lymphocyte counts in a significant number of women⁸. A United States label for one product states that ipriflavone may slow the metabolism of theophylline, and another label asks users of hormone replacement therapy to consult a healthcare professional before use⁶.

Last updated October 16, 2026. Read how we make monographs.

In the full monograph

44 sources, 38 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources