This study is a randomized, double-blind, placebo-controlled, single dose, escalation, phase I clinical trial to evaluate the safety and tolerability of recombinant human follicle stimulating hormone Fc fusion protein injection (TWP-201) in healthy female subjects. The objective of the trial is to evaluate the safety and tolerability of TWP-201 in healthy female subjects.

Inclusion Criteria:

• Body weight ≥ 45 kg, 19 ≤ body mass index (BMI) ≤ 28 kg /m2;
• Women with sexual experience, potential fertility and regular menstrual cycle (25-34 days) (including boundary value);
• The levels of sex hormones were normal or abnormal without clinical significance at the time of screening;
• The physiological structure of uterus and bilateral ovaries was normal or abnormal by ultrasound examination, without clinical significance;

Exclusion Criteria:

• Known the history of stage III / IV endometriosis, submucosal myoma and endocrine abnormality within 6 months before enrollment;
• Known the history of ovarian hyperstimulation syndrome (OHSS);
• Premature ovarian failure, decreased ovarian reserve function (Antral Follicle Counting < 3), high ovarian response, polycystic ovary syndrome, unexplained vaginal bleeding or endometrial hyperplasia;
• Any FSH or HMG preparations were used within 3 months before the first study;
• Pregnancy or lactating women.