Inclusion Criteria:
1. Be able to sign the informed consent form before any study-related procedures are performed, and be willing and able to comply with the study requirements;
2. Premenopausal female subjects, aged 18-50 years, including 18 and 50 years;
3. Have regular menstrual cycles in the past 6 months, with a menstrual cycle of ≥21 days and ≤35 days, and a menstrual period duration of ≤14 days;
4. Meet the diagnosis of abnormal uterine bleeding and agree to be admitted for treatment. Assessed by the alkaline hemoglobin method, in 2 consecutive menstrual cycles during the screening period, the menstrual blood loss is \>80 ml in both cycles; or the blood loss in any one cycle is ≥160 ml;
5. The pregnancy test result is negative before randomization;
6. Those with a body mass index \[BMI = weight (kg) / height² (m²)\] of 18.5-28.0 kg/m² (including the boundary values).
Exclusion Criteria:
1. Patients with known endometrial polyps \> 1.5 cm, endometrial malignancy, or atypical hyperplasia;
2. Patients with known or investigator-determined ovulatory dysfunctional abnormal uterine bleeding who require hormonal therapy;
3. Patients identified by investigators as having iatrogenic abnormal uterine bleeding;
4. Patients with abnormal uterine bleeding related to coagulation dysfunction, including but not limited to those with laboratory test results showing: platelet count ≤ 100×10⁹/L, or APTT prolonged by ≥ 10s beyond the upper limit of normal, or PT prolonged by ≥ 3s beyond the upper limit of normal;
5. Patients with bleeding caused by cervical or vaginal lesions;
6. Patients who have undergone major surgery within 6 months prior to screening;
7. Patients determined by investigators before randomization to require surgical treatments such as total hysterectomy, myomectomy, hysteroscopic treatment, uterine artery embolization, or ablation during the study period;
8. Patients who have received the following medications within 3 months prior to randomization: gonadotropin-releasing hormone agonists; sex hormone drugs administered orally, by injection, vaginally, or transdermally (including but not limited to drugs containing estrogen or progesterone); selective estrogen receptor modulators; hormonal intrauterine devices (LNG-IUS). For long-acting (3-month) gonadotropin-releasing hormone agonists or progesterone preparations, the last administration must be no later than 6 months prior to randomization;
9. Patients who have used danazol, desmopressin, tranexamic acid, aminocaproic acid, or traditional Chinese medicines for the treatment of menorrhagia within 3 months prior to randomization;
10. Patients who need to receive anticoagulants (e.g., warfarin, heparin, etc.) or antiplatelet therapies (e.g., clopidogrel, ticagrelor, etc.) during the study period;
11. Patients with intolerance or contraindications to BT-114143 Injection;
12. Patients who have participated in clinical trials of other investigational drugs, biological agents, or medical devices and received therapeutic interventions within 30 days prior to screening;
13. Patients with clinically severe diseases such as known disorders of the circulatory, endocrine, nervous, digestive, respiratory, urinary, hematological, immunological, psychiatric, or metabolic systems, as assessed by investigators as unsuitable for participation in the trial;
14. Patients with a known history of glaucoma or retinopathy, as assessed by investigators as unsuitable for participation in the trial;
15. Untreated or poorly controlled thyroid dysfunction, except for mild subclinical hypothyroidism (i.e., TSH \< 10 mIU/L with normal FT4 and TT4);
16. Patients with a known history of thrombotic diseases, including but not limited to pulmonary embolism, deep vein thrombosis, etc.;
17. Patients diagnosed with malignant tumors within the past 5 years, except for cured basal cell carcinoma of the skin;
18. Patients with cervical cytology results indicating a risk of cervical cancer within 1 year prior to the screening period and requiring treatment.
19. Patients with one or more of the following abnormal laboratory test results before randomization:
* Alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) \> 1.5 × ULN;
* Total bilirubin \> 1.5 × ULN, except for patients with Gilbert's syndrome;
* eGFR ≤ 60 mL/min/1.73 m² (calculated using the CKD-EPI formula);
* Hemoglobin \< 90 g/L;
20. Patients with known infection of human immunodeficiency virus (HIV), or positive hepatitis B surface antigen (HBsAg), or positive hepatitis C virus antibody (HCV Ab);
21. Alcohol abusers (i.e., consuming more than 14 standard units of alcohol per week within 3 months before screening (1 standard unit contains 14g of alcohol, such as 360ml of beer, 45ml of spirits with 40% alcohol content, or 150ml of wine)), or those with a history of drug abuse (such as morphine, tetrahydrocannabinolic acid, methamphetamine, 3,4-methylenedioxymethamphetamine, ketamine) within 1 year before screening, or with mental or neurological diseases that investigators consider may affect participation in the study;
22. Pregnant or lactating women, or subjects who had unprotected sex within 14 days before screening;
23. Subjects who have plans for pregnancy from the time of signing the informed consent form until 3 months after the last administration, or subjects (or their partners) who are unwilling to take effective contraceptive measures (specific contraceptive measures are shown in Appendix 1);
24. Patients with any condition or result that investigators or designated personnel consider may pose a risk to subjects or the implementation of the study;
