This study is a double-blind crossover study in female healthy volunteers to compare the pharmacokinetics and safety of a single dose each of two different formulations of Proellex for oral administration. Each formulation will be designated as either Treatment A or Treatment B. A total of 12 subjects who meet the eligibility criteria will be randomized to receive either Treatment A or Treatment B as their first assigned treatment. After a 7-day washout period subjects will receive the alternative treatment. On the day of each treatment subjects will remain in the clinic overnight and undergo 72-hour pharmacokinetic assessment at the following time points: 0, 0.5, 1, 2, 3, 4, 8, 12, 16, 24, 48 and 72 hours after administration of study drug.

Inclusion Criteria:

1. Speak, read, and understand English or Spanish and is willing and able to provide written informed consent on an IRB-approved form prior to the initiation of any study procedures;
2. Healthy, premenopausal female age 18-47;
3. History of menstrual events that occur in regular cycles
4. Agreement not to attempt to become pregnant
5. Agrees to use double-barrier contraception during the study and for 30 days after discontinuation of study medication. Acceptable double-barrier methods are: male condom with spermicide; male condom with diaphragm; diaphragm containing spermicide plus additional intra-vaginal spermicide;
6. Has a negative pregnancy test at the Screening visit. An exception for the pregnancy test requirement will be granted for subjects reporting surgical sterilization in medical history
7. Normal laboratory values or clinically insignificant findings at screening as determined by the Investigator;
8. Subject is willing to remain in the clinic overnight for PK assessment on Days 0 and 8
9. Ability to complete the study procedures in compliance with the protocol.

Exclusion Criteria:

1. Subject is a post-menopausal woman, defined as either; six (6) months or more (immediately prior to screening visit) without a menstrual period, or prior hysterectomy and/or oophorectomy
2. Subject is pregnant or lactating or is attempting or expecting to become pregnant during the study
3. Women with abnormally high liver enzymes or liver disease. (ALT or AST exceeding 2.0 x ULN AND total bilirubin exceeding 1.5 x ULN at screening and confirmed on repeat).
4. Received an investigational drug in the 30 days prior to the screening for this study
5. Women with a history of PCOS
6. Concurrent use of any testosterone, progestin, androgen, estrogen, anabolic steroids, DHEA or hormonal products for at least 2 weeks prior to screening and during the study.
7. Use of oral contraceptives in the preceding 2 weeks. Use of Depo-Provera® in the preceding 10 months.
8. Has an IUD in place
9. Women currently using narcotics
10. Women currently taking spironolactone
11. Infectious disease screen is positive for HIV or Hepatitis A, B or C.
12. Clinically significant abnormal findings on screening examination or any condition which in the opinion of the investigator would interfere with the participant's ability to comply with the study instructions or endanger the participant if she took part in the study