Cyclical mastalgia of moderate to severe degree requires systemic drug therapy. Tamoxifen is the drug of choice worldwide. A novel molecule, centchroman/Ormeloxifene, developed in India, was found to be equally effective in previous studies. However, its optimal dose regimen is uncertain. We conducted three-arm randomized controlled trial to compare the effectiveness in relieving breast pain. Group 1 received tamoxifen 10 mg daily, and groups 2 and 3 received centchroman 30 mg twice and 30 mg thrice a week, respectively, for 3 months with a follow-up of 3 more months. Breast pain score, nodularity score, sonographic evaluation of the breasts and ovaries, quality of life scores, and adverse events were recorded. The number of patients enrolled was 32, 31, and 30 in group 1, group 2, and group 3, respectively. All three groups had significant improvement in breast pain scores [group 1 (5 → 2), group 2 (5 → 2), group 3 (6 → 2), p < 0.001)], nodularity scores [group1 (1 → 0), group 2 (1 → 0), group 3 (1 → 0), p < 0.001)] and in the quality of life scores over time. However, no significant differences were observed in-between the groups. Transient ovarian cyst formation and menstrual irregularities were more common with a higher dose of centchroman. Centchroman in the dosages of 30 mg twice or thrice a week is as effective as a daily dose of tamoxifen 10 mg in relieving pain, nodularity, and improving quality of life scores. The dose of centchroman 30 mg twice a week for 12 weeks has the least adverse effects and should be accepted as the optimal dosage regimen. There is a need of further study with a greater number of participants and longer follow-up. Trial registration number: CTRI/2018/02/012043 (Registered on: 21/02/2018).

中度至重度的周期性乳腺痛需要全身药物治疗。他莫昔芬是全球首选药物。在印度开发的一种新型分子 centchroman/Ormeloxifene 在之前的研究中被发现同样有效。然而，其最佳剂量方案尚不确定。我们进行了三臂随机对照试验，以比较缓解乳房疼痛的有效性。第 1 组每天接受他莫昔芬 10 mg，第 2 组和第 3 组分别接受 centchroman 30 mg 每周两次和 30 mg 每周三次，持续 3 个月，随访 3 个月以上。记录乳房疼痛评分、结节评分、乳房和卵巢的超声评估、生活质量评分和不良事件。第 1 组、第 2 组和第 3 组的入组患者人数分别为 32、31 和 30。p  < 0.001)]、结节评分 [第 1 组 (1 → 0)、第 2 组 (1 → 0)、第 3 组 (1 → 0)、  p  < 0.001)] 以及随时间推移的生活质量评分。然而，在各组之间没有观察到显着差异。较高剂量的 centchroman 更常见一过性卵巢囊肿形成和月经不规则。每周两次或三次 30 毫克剂量的 Centchroman 在缓解疼痛、结节和改善生活质量评分方面与每天服用 10 毫克他莫昔芬一样有效。centchroman 30 mg 每周两次，持续 12 周的剂量具有最少的副作用，应被接受为最佳剂量方案。需要更多的参与者和更长的随访时间进行进一步的研究。试用注册号：CTRI/2018/02/012043（注册日期：21/02/2018）。