Flavonoid glycoside isolated from justicia gendarussa. Primary active compound responsible for contraceptive effect.
Class: flavone glycoside
Source: Justicia gendarussa (Acanthaceae), leaf fraction
mechanism
Competitive inhibitor of hyaluronidase on the sperm acrosome. Hyaluronidase is the enzyme sperm use to penetrate the cumulus oophorus layer surrounding the egg. Gendarusin A binds the active site and blocks penetration without affecting sperm motility or production.
Effect is dose-dependent and reversible. No androgenic or estrogenic activity reported.
pharmacokinetics
Onset: ~90 days of daily dosing to reach sustained inhibition
Reversibility: function returns within ~90 days of cessation
Dose in clinical trials: 213–285mg/day standardized extract (70% ethanol)
clinical evidence
Phase II/III trials, Universitas Airlangga, Surabaya, Indonesia. 186 men, 108-day protocol. Efficacy: 99.6% (1 pregnancy). No significant adverse effects reported.
related
apigenin — co-occurring flavonoid in the same plant, COX-2 inhibitor
cumtea — consumer product delivering both compounds