(04-12-2012, 02:59 AM)LookingForward2NBE Wrote: The T1/2 (half-life) of a drug you are correct that reflects the time a body requires to eliminate (or deactivate is better representation of what actually happens) 1/2 of the drug from your system.
Here are some important things to take into consideration when looking at T1/2:
1. You need to know what the ED50 (effective dose in 50% of the population is)
2. You need to know what the LD50 (lethal dose in 50% of the population) is)
3. The spread between the ED50 and LD50 will provide you with an indication of the safety profile of the drug. If it`s a narrow therapeutic drug that difference between the LD50 and ED50 will be smallish and the dose that is effective and can be lethal is very close to one another and you need to be very careful on controlling the dosage..
Research has failed to establish a LD50 for PM, even though it has been attempted using animals models. See this search:
http://scholar.google.com/scholar?hl=en&q=LD50+for+pueraria+mirifica&btnG=&as_sdt=1%2C39&as_sdtp=
As you note later, there are no good studies looking at the effects of estradiol in males let alone PM, so an ED50 seems highly speculative. Just from the reports on this forum, the ED seems to be extremely variable on an individual basis, with some being relatively sensitive while others highly resistant to the effects of PM/deoxymiroestrol. In any case, since research has failed to establish an LD50, the spread between each individual's ED50 and LD50 is perforce VERY wide, and hence relatively safe from a toxicity perspective.
(04-12-2012, 02:59 AM)LookingForward2NBE Wrote: 4. You need to understand whether maintaining a steady-state concentration of the drug is desirable (the blood levels are maintained in a narrow band) - as is the case with Antibiotics to ensure a proper and effective kill rate of pathogens or if it should be dosed in a classic bell curve where it rises and falls giving your body a chance to rest which is typically 3x the half-life. For a 4hr t1/2, you would be prescribed 2x BID (twice a day) or every 12 hours.
That's OK if you truly need to give your body a "rest." Again, this is unknown with PM/deoxymiroestrol and likely unnecessary as explained below. (Also, 2x BID is redundant at best if not outright confusing, rather like saying ATM machine. The correct terminology would be PO BID.)
Also, desirability of maintaining a steady state will vary depending on an individual's responsiveness to PM and their respective goals. I think Bryony has arrived at distinctly different goals (than he even started out with) in taking PM from many other folks, and seems to require a higher ED with a more frequent administration schedule. It seems as if with his physiology and goals he needs a steady state.
(04-12-2012, 02:59 AM)LookingForward2NBE Wrote: With hormones, from what I understand you do not want to be hitting steady-state and dosing on the half-life as you will cause several negative feedback loops and cause a cascade of hormonal responses that will have very negative consequences.
There is a great deal of controversy on just this topic in the MtF transgender community. From the accounts I have read, it seems like most TS women report better long term results when they attempt to maintain something like a steady state level of estradiol administration. Depending on administration method, most probably do have some kind of cycling of serum hormone levels rather than a true steady state, but it is also almost certainly a much shorter cycle than natal women experience. Many, if not most TS women maintain this administration schedule over years with no apparent deleterious effects. Physician monitoring of HRT dosages via serum hormone levels is often done on a quarterly or semi-annual basis with a consistent administration schedule considered optimal in each interval. This seems pretty close to a steady state to me.
This is my subjective evaluation of subjective reports I have read, as you are right, there are few if any studies looking at this. Do remember that the goals of a TS woman are physiologically different than a natal woman whose monthly cycle with its ebb and flow of hormone levels serves a biological purpose that males and TS women are unable to achieve. Experience suggests it is NOT necessary to mimic that cycle to achieve and maintian partial or complete feminization in males.
(04-12-2012, 02:59 AM)LookingForward2NBE Wrote: That being said - there is probably very very few doctors or research papers are available on the effects of high constant levels of female hormones in biological males. I would guess that it would lead to several estrogen cancer concerns, a lose of sex drive, significant atrophy of testis and penis and probably a negative cognitive effect as well (decreased attentation etc.)
In my opinion, except for the part regarding atrophy of the testes, the rest of that last part is largely urban myth. Reduced sex drive is very variable on an individual basis and the penis does not actually atrophy. The ability to continue to achieve erections is also highly variable, with many reporting no decrease in tumescence or length.
Any increased estrogen-sensitive cancer risk comes mainly from use of synthetic estrogens (such as DES, Premarin and few others) in combination with synthetic progestins (as versus bio-identical, micronized progesterone.) Bio-identical estradiol and micronized progesterone either alone or in combination do NOT have the same health risks as synthetics, and from all the evidence I have come across so far, PM apparently shares this low risk for negative side effects.
While it seems apparent from research that estradiol and testosterone affect distinct cognitive domains, I think it is a reach to consider the evidence for "negative" effects conclusive. Saying there are negative effects of estrogenic compounds on cognition would also imply that natal female cognitive strengths are "negative" in comparison to male cognitive strengths. Again, in my opinion this is not validated by research.
Finally, we are talking about an estrogen mimic, not pharmaceutical or even bio-identical hormones. While PM exhibits high estrogenic activity (
http://scholar.google.com/scholar?q=estrogenic+activity+of+pueraria+mirifica&btnG=&hl=en&as_sdt=0%2C39) it is not a given that it behaves exactly the same as estradiol in all ways, though I suppose a conservative interpretation would be to think of it that way until proven otherwise.