Hi shopping queen
I'm a bit late to this thread but I took Cyclogest for about 4 years from approx 2007 - 2011. This was prescribed by the NHS GP (who had a special interest in gynaecology) before utrogestan was generally available or known about - in fact I told her about utrogestan in late 2011!
It is designed for both rectal and vaginal use and comes in 200 mg or 400 mg capsules.
As far as I know there is very limited research on its use in HRT. When I first took it I wrote to the manufacturer - I think it was Ferring at the time but might be mistaken, and they sent me some information but unfortunately I didn't save it and the e-mail is on my old computer.
Therefore I would suggest, unless there has been more research, that the dosage is guesswork, or trial and error based on the equivalent amount of Utrogestan.
I was prescribed 400 mg for 11 days per 28 day cycle. I used to get a regular withdrawal migraine so always timed it for the weekend so I would be able to work...
As with any progestogen used vaginally vs other methods, theoretically less should be needed compared with other methods ( rectal, oral) for protection of the uterus since the first "hit" is the womb, rather than being transported through the bloodstream ( via the upper digestive system in the case of utrogestan, via the rectum in the case of cyclogest).
In terms of systemic absorption - I had a google and found this study:
https://pubmed.ncbi.nlm.nih.gov/22714063/Although it was looking at the use of cyclogest in fertility and so the conditions are different, involving embryo transfer - nevertheless systemic levels were compared between vaginal and rectal administration:
"147 patients who underwent intra-cytoplasmic sperm injection cycle were randomized on the day of the embryo transfer (ET) by a computer-generated randomization program to receive 400 mg of Cyclogest either vaginally or rectally twice daily for up to 8 weeks."
"There were no significant differences in serum P concentration 6 days after ET, "(ET - embryo transfer)
When I took it, I used to put one (x 200 mg) up the front and one up the back! I really did not like the rectal route and the effect in the morning....(details would be TMI!).
I would imagine it is not advisable to cut the capsule unless under medical supervision and proper regular monitoring of the uterus lining - perhpas when very low oestrogen doses are used? It depends how the progesterone is distributed through the capsule itself.
Progesterone is a sedative so the tiredness is a necessary evil, because higher doses need to be taken daily in order that sufficient gets to the uterus - it breaks down quickly in the blood.
I hope this helps and all the best with it!
Hurdity x
PS Just to add that Cyclogest is available on NHS but will be off-licence for HRT, so a specialist private prescription may be needed initially though a £30 e-mail consultation to Dr Currie asking her specifically about this - might do the trick (cheaper than a private consultant!).