Thanks bear. I read about this a few weeks ago I think when someone posted about a different progesterone product available for ? contraception in some Third World countries in South America - (Brazil or Chile perhaps - can't remember?) - vaginal ring I think. I didn't post then (about the Yimaxin then because I thought it had limited applicability other than academic – but interesting that there are other products already available. Personally though I would want to see something developed closer to home because of supply chain issues – although many of such products are exported worldwide. As we have our own progesterone products in EU I can imagine there hasn't been a need – although I would want to see more companies producing (generic) progesterone formulations - but in EU.
Also they mainly studied systemic absorption – when in fact it is the amount that gets to the endometrium which is critical when used as part of HRT. The conclusion that the absorption of Yimaxin vaginally was superior to that of Utrogestan I don't think is justified when you apply that principle to the endometrium. They gave an explanation for the lower systemic absorption of Utrogestan – that this was due to the formulation of the capsules which inhibited absorption through the vagina – but there was no comparison (between vag Utro and Yimaxin) about endometrial concentrations which is the crucial parameter followed by thickness etc after oestrogen.
I think the aim of the study was still for it to be applicable to its use for luteal support and compare this to utrogestan.
The things is 50 mg progesterone in one product is not the same as 50 mg in another – especially when talking about a hard pessary vs soft capsule. For example if you compare the amounts needed for luteal support different doses are needed depending on the product – I've posted about that in the past. Research needs to be done on endometrial protection as part of HRT with any number of products.
So if they are comparing 50 mg and saying it is similar to 100 mg utrogestan ( although we don;t know re endometrial protection) – and even saying the systemic absorption of this lower dose product is HIGHER, then we are no further forward because it is the lower dose progesterones that will give endometrial protection with LOWER systemic absorption that we are interested in – so a 50 mg Utrogestan capsules and perhaps a return of the 4 % Crinone gel. Higher systemic absorption wil give more side effects.
Complicated when you look beyond the conclusion....
Hurdity x
Hi there,
Unlikely 'academic' when 4.75 million women are using it.
Unlikely 'for it to be applicable to its use for luteal support and compare this to utrogestan' when all the 16 subjects are postmenopausal women
![Grin ;D](https://www.menopausematters.co.uk/forum/Smileys/extended/grin.gif)
'On day 21, drugs (estrogen and progesterone) were discontinued, fasting blood samples collected, and
specimens of endometrium collected and examined independently by two experienced pathologists.'
'Orally administered Yimaxin is rapidly metabolized during first liver pass and then disappears from the general circulation. On the other hand, vaginal-route Yimaxin reaches higher progesterone concentrations in
endometrial tissue than oral-route Yimaxin'
I suppose that answers your concerns about 'endometrial protection'.
They are not comparing 50mg Yimaxin with 100mg Utrogestan, they are comparing 200mg of both drugs.
Regarding the systemic absorption, since Yimaxin has HIGHER VAGINAL ABSORPTION than Utrogestan, it's likely that lower doses could be enough for endometrial protection and I expect further studies will be carried out to assess this possibility. This is just a small preliminary study.
'Personally though I would want to see something developed closer to home because of supply chain issues – although many of such products are exported worldwide.' Pharmaceutical companies are global, the small local ones are going to be acquired or merged sooner or later. Supply chain issues are usually related to raw materials, not finished products and most raw materials used by manufacturing sites in Europe and the UK come from China or India, so nothing will change unless the raw materials are also produced locally, which is unlikely in the near future due to high costs.
This statement has caught my attention: 'Because blood-drug concentration is low after a single dose, the general single-dose protocol is not suitable for clinical use, but twice a day is usually selected in clinical practice, which is adopted for PK study' I wonder if this is why one single daily dose of Utrogestan causes so many nasty side effects.
'Third World countries' are called developing countries.
![Wink ;)](https://www.menopausematters.co.uk/forum/Smileys/extended/wink.gif)
BeaR.