I started injections of Depo-provera (synthetic projesterone) about 4 months ago. I had to cut back on my use of spiro because my diet of fresh foods contrubuted too much potassium. I immediately felt better, and soon noticed an increase in that sensitivity denoting a potential breast growth spurt. Much welcome after 5 years on HRT. My libido has increased quite a bit. Your mileage may differ.
Now as far as synthetic vrs. bio-identicles, you and your doc may want to investigate. Suzanne Summers has made a fortune flogging bio-identicals and written several best selling books, she was on Oprah. There is another side though.
"The American College of Obstetricians and Gynecologists, the Endocrine Society, the North American Menopause Society (NAMS), United States Food and Drug Administration and the Mayo Clinic have released statements that there is no expected difference in benefits or risks of hormone replacement therapies using bioidentical molecules compared to those using non-bioidentical molecules, and also that compounded hormone products may have additional risks related to compounding. While CHRT and FDA-approved BHRT products have been extensively studied and are heavily regulated, compounded BHRT products are unregulated and lack an accepted evidence base.[3][5][14][15][16][17] Since pharmacy-compounded products are not subject to FDA testing and quality control measures, their potency, purity and safety have been questioned.[8]
This is from the Wiki-please read up.