Pilot of Letrozole for Uterine Myomas

Inclusion Criteria: 1. ≥21 years old 2. Premenopausal (at least one menses in last 3 months) 3. Symptomatic fibroids (fibroids visualized on ultrasound or MRI and heavy uterine bleeding, pelvic pressure or discomfort, urinary or bowel abnormalities, dyspareunia) 4. Fibroids that are ≤4 in total number or Fibroids that are ≤7 in total number if all fibroids are less than 4cm (40 mm) each 5. Fibroids that are ≤7cm in maximum diameter, on screening imaging, if ≤4 fibroids in total number(fibroid is defined as any mass with radiographic characteristics of fibroid \>2cm) 6. Up to date in Pap smear screening and surveillance 7. Endometrial biopsy (required if age\>45 years with irregular bleeding) does not indicate premalignant or malignant cells 8. Agree to use non-hormonal barrier method of contraception during study period if at risk for pregnancy 9. Has primary care provider or gynecologist 10. Agrees not to start new medications/treatments for fibroids during the study 11. Able to give informed consent Exclusion Criteria: 1. Fibroids treated by surgery, radiologic procedure, or GnRH agonist or antagonist in the last 3 months 2. Any submucosal fibroid ≥2cm that is \>50% in uterine cavity (FIGO Type 0 or Type 1 fibroids) amenable to hysteroscopic resection 3. Use of exogenous estrogen and/or progestin in the last month. (for 3 month long-acting depoprovera injection, no use in last 3 months) 4. Pregnant, lactating, or planning to become pregnant in the next 6 months 5. Hematocrit \<27% or visit to emergency room or hospitalization for fibroid symptoms in the last 3 months (cannot be safely randomized to a placebo) 6. History of osteopenia or osteoporosis 7. History of hyperlipidemia 8. Current liver or kidney disease 9. Unable or unwilling to attend 4 study visits 10. Pelvic imaging concerning for gynecologic cancer or cancer of the genitourinary or gastrointestinal system 11. Does not have primary care provider or gynecologist