I will be glad to help you find an answer. Please give me a minute to research your question.

Sorry, having some technical difficulties.

Cenestin is a Conjugated A/Synthetic Estrogen whereas is Conjugated B/Synthetic Estrogen.

Both are estrogen derivatives though somewhat different.

You may experience some transition.

I am looking for some information on this I can share with you. The first pertains to B. The link is: http://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=24075#nlm42230-3.

It states: "ENJUVIA® (synthetic conjugated estrogens, B) tablets contain a blend of ten (10) synthetic estrogenic substances. The estrogenic substances are: sodium estrone sulfate, sodium equilin sulfate, sodium 17α-dihydroequilin sulfate, sodium 17α-estradiol sulfate, sodium 17β-dihydroequilin sulfate, sodium 17α-dihydroequilenin sulfate, sodium 17β-dihydroequilenin sulfate, sodium equilenin sulfate, sodium 17β-estradiol sulfate, and sodium Δ8,9-dehydroestrone sulfate."

The second pertains to A. The link is: http://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=1cd07b54-f66f-4040-9058-462324267196

It states: "Synthetic conjugated estrogens, A tablets contain a blend of nine (9) synthetic estrogenic substances. The estrogenic substances are sodium estrone sulfate, sodium equilin sulfate, sodium 17α-dihydroequilin sulfate, sodium 17α-estradiol sulfate, sodium 17β-dihydroequilin sulfate, sodium 17α-dihydroequilenin sulfate, sodium 17β-dihydroequilenin sulfate, sodium equilenin sulfate and sodium 17β-estradiol sulfate."

Basically, they contain different estrogen mixtures. Please give me a minute to compare more in depth.

Yes, I am still here. Still researching. Concentrations most probably are different.

Was this change made at the request or approval of your physician?

You may experience some differences transitioning, however, I don't expect you will experience a major difference.

When dealing with hormones it is difficult to state for certain.

I would not advise changing back and forth between the two. Once your body becomes accustomed to one, it would be best to stay with that particular formulation/

Does this help?

To your earlier question, I would not expect weight gain to be an issue if this was not experience on the Cenestin.

I am sorry this question was not answered to your satisfaction. I did not see your question with respect to the reason for unavailability until now. No drug shortage has been reported to the FDA.