Postmenopausal obesity is characterised by increased visceral fat accumulation due to oestrogen deficiency. Biancaea sappan L. Tod contains brazilin and other compounds with antioxidant and anti-obesity potential. This study aimed to evaluate whether fermentation of B. sappan extract into sappan cider using SCOBY could enhance its biological activity. Fourty-eight OVX female rats were divided into eight groups: SHAM, OVX, TAM (tamoxifen 1 mg/kg body weight [BW], positive control), Biancaea sappan extract (BSE) (20 mg/200 g BW), KOM (standard kombucha 1 mL/200 g BW), and CID I–III (B. sappan cider 0.93, 2.8, and 5.6 g/200 g BW, respectively). Oral treatment was administered for 28 days. Phytochemical profiling by gas chromatography–mass spectrometry (GC–MS) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) showed that fermentation converted brazilin to brazilein and increased the total phenolic content. Compared with OVX rats, CID III significantly (p < 0.05) decreased bodyweight gain, visceral fat mass, and adipocyte diameter, while enhancing superoxide dismutase (SOD) activity and reducing malondialdehyde (MDA) and interleukin-1β (IL-1β) levels. No uterotrophic effects were observed. CID III was the most effective dose for reversing obesity-related changes without hormonal stimulation. These findings indicate that SCOBY-fermented B. sappan cider improves redox balance and adiposity, suggesting its potential nutraceutical for managing postmenopausal obesity. © 2025 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.