Cessation of menstrual bleeding is a frequently encountered gynecologic disorder among women in the reproductive age. A recent study published in Current Drug Discovery Technologies determined the efficacy of an herbal tea based on Foeniculum vulgare (fennel), in inducing regular bleeding in women with oligomenorrhea and secondary amenorrhea (oligo/amenorrhea). Overall, 40 women aged 18-40 years with oligo/amenorrhea were randomized equally into two groups. Women in group 1 were treated with Foeniculum vulgare/Mentha longifolia/Vitex agnus-castus herbal tea 11.2 g/day in 2 divided doses for 2 weeks and group 2 received medroxyprogesterone acetate (MP) 10 mg/day for the last 10 days of their menstrual cycles. The intervention was repeated in three cycles of menstruation in both groups.

There were 83.3% women with bleeding during the first cycle in the herbal tea group and 94.1% in the MP group. The regularity of bleeding showed no significant difference in patients treated with herbal tea from those given MP (66.7% vs. 94.1%; p = 0.088). Mean interval of cycles was found to decrease in both groups after intervention. Mean duration decreased significantly in MP group following the intervention; however, it was not different in patients treated with herbal tea. The difference between the two groups was not significant (P=0.705). Volume of blood flow, with regard to Pictorial Blood Assessment Chart (PBAC), was found to increase significantly in MP group after the intervention (P=0.001) and it was not different in patients treated with herbal tea (P=0.757); however, the difference between 2 groups was not significant (P=0.063). The percentage of patients with on time menstruation in the next (drug-free) episode was 50% in the herbal tea group compared with 23.5% in the MP group (p = 0.105). Secondary outcomes including dysmenorrhea, acne and hirsutism were reduced in the herbal tea group (P≤0.05). These outcomes were increased in the MP group (P=0.007). At treatment end, a significant decrease in luteinizing hormone, total testosterone and free testosterone was noted in patients given herbal tea. There was a significant decrease in endometrial thickness in both groups after the intervention (P=0.001); however, the difference between the two groups was not significant (P=0.58). No notable complication or side effect was reported with herbal tea use.

Foeniculum vulgare/Mentha longifolia/Vitex agnus-castus herbal tea was thus found to be safe, well-tolerated, and effective in inducing bleeding and maintaining regular bleeding in women with oligo/amenorrhea.