I have heard that the half life on subligual Estradiol is about 4 hours. I will be chatting with my endo about levels in April, and this would be useful information before I look like an idiot with him.
Any thoughts? Anyone can validate?
No self med stuff here. I just want to understand my serum levels when we talk and if he suggests injections as I prefer the pills.
With sublingual, levels peak during the first hour and then decline quite abruptly and quickly the next few hours. Levels fluctuate alot, short-life is short. So, it is usually advised to take pill sublingually more than twice daily, at least.
I noticed a marked improvement when I started cutting my pills. Not only does it keep a more constant amount of E in your system, but it also makes them dissolve much quicker, which at least in my case I am sure has led to less loss of E to my stomach.
Now you mentioned injections it should be noted that injections are usually estradiol valerate, rather than plain estradiol. Valerate means it is an ester of normal estradiol, and this ester is basically a chemical that binds to the estrogen and prevents it from being absorbed until it is broken down by the body. Once the body breaks the ester down your body will be able to make use of the estrogen.
In effect what this does is keep the injection active much longer than it would if you were to take straight estradiol pills ground up and injected, because if that were what where happening you would need like 4 shots a day or something to keep any consistent level. In effect this means injections can have effects much longer than the pills because they are bound to an ester.
I think the reason that an injection of estradiol valerate is long lasting is not so much because of the ester since with valerate, it is quickly broken down to estradiol upon entrance into the blood in comparison to estradiol cypionate or polyestradiol phosphate, for example. The reason it lasts long (usually a week before PMS symptoms start to creep up) is because the solution is injected into the muscle from which it is gradually released into the blood. The muscle acts as a depot, a reservoir.
Both have an effect, it doesn't matter the route of injection it still isn't usable without being broken down into estradiol and valeric acid. Different esters take different times to break down and be usable regardless of if they are intramuscular or not. Obviously it is going to be given in an intramuscular injection.
The big differece is between say estradiol valerate and estradiol cypionate is that it is much easier to break down the ester of valeric acid than cypionic acid partially due to the lipophilic nature of cypionic acid since it can actually get stored in the fat and released over time from an additional mechanicasm than estradiol valerate.
My point is, the ester used matters a fair bit as into how quickly it is converted into usable estradiol, valerate isn't super long lasting, but is longer than not any ester at all, you can easily see this in that using the same intramuscular injection sites the different esters have different times they will last.
I just think, based on what I read from various sources, that estradiol valerate upon entering the blood, quickly breaks down into estradiol so that being esterified with valerate once in the blood means absolutely nothing and doesn't prolong its life once released from the muscle. It's the fact that it remains in the muscle because it's esterified (lypophylic tail, ester keeps it in oil in muscle) that prolongs its life when it's injected (and released gradually) vs when it's taken orally. Orally, estradiol (Estrace, Estrofem) and estradiol valerate (Progynova) have both quite similar pharmacokinetics, bioavailabilities, half-lives so the ester doesn't prolong or increase its effects.
Due to the finances involved and due to the way I respond to estrogen crash - badly, my energy levels totally tank - I wanted to track what was happening through the day. I am not sure I would respond well to weekly E crashing. Hence the question on half life, I am curious, more than anything else, what my levels are doing on current doses.
It certainly has been working for me on sublingual. The physical changes are marked and the psychological/emotional side is excellent.
I only crash for about an hour in the morning and that's because of a planned delay in the first dosage to allow physical vocal excercizes.
Thanks again for the responses, would be curious if there is other input. Or reaction to the injected crash question.
There's only a crash if you don't inject frequently enough. Sublingual is worst actually, as levels fall much quicker and abruptly. So, if you are fine on sublingual, then you'll be fine on injections.