‘Subcutaneous’ means ‘beneath the skin’, and this is how the implant works. A tiny pellet, about the size of the tip of a lead pencil, is inserted under the skin of the lower abdomen. The technique is simple, takes about 5 minutes, and can often be carried out in a general practitioner’s surgery under a local anaesthetic, leaving little or no mark. The big advantage of an implant is that, once it has been inserted, you can forget about it for several months. No need to take tablets or change patches. Unlike other forms of HRT, it can also be combined with small quantities of the hormone testosterone if your doctor thinks this would help you. Although testosterone is the male hormone, it is also produced in the ovaries of women, so it is not unnatural to receive it. It can be helpful for women who have certain psycho-sexual problems, a drop in libido (interest in sex), much reduced energy levels or severe loss of confidence. Being a male hormone, it may cause a slight increase in facial hair.
Nearly all women with implants gain relief from hot flushes, and three-quarters gain relief from depression. Improved collagen levels lead to better skin and stronger bones.
As with the patch, the oestrogen is released straight into the bloodstream, and avoids the digestive system, so a lower dose can be used, giving fewer side-effects than oral HRT. There is no question of forgetting to take it, or of suffering the skin irritation some women get with the patch. It also avoids the necessity of ‘popping a pill every day’, which is what many women don’t like about HRT; until it needs replacing you can forget you are using it at all. It also offers good protection against osteoporosis, except at the lowest dosage.
The implant does not last forever, and it will need to be replaced every 4-6 months, depending on when the level of oestrogen in the implant falls and the menopausal symptoms return. You will need to return to your GP or gynaecologist for a replacement Although this may seem rather a nuisance, it does ensure that you are regularly monitored, and a check-up may also detect irregularities that might otherwise have gone unnoticed.
This condition is called tachyphylaxis, and has received unfavourable publicity following reports of some recent research into it One or two newspapers decided that it suggested the women were ‘addicted’ to oestrogen, because they needed ever-higher doses at ever-more-frequent intervals. “
The problem of tachyphylaxis should not, however, be dismissed as irrelevant, because for the small minority of women affected by it, it can be a serious disadvantage, and one for which doctors can’t at present agree on a solution. Simply to refuse further HRT in any form produces a return of the symptoms and much suffering; it may also be a dangerous approach in women whose falling oestrogen is producing feelings of depression. However, to replace the implant at ever-closer intervals in a woman whose oestrogen level may be well above normal is not desirable either. It is obviously an area in which more research is needed. If you feel you are developing this condition, talk to your doctor about a gradual withdrawal from this type of HRT, as a different type might be the solution for you. He may decide to monitor your blood oestradiol level regularly, and to replace the implant when it falls to a certain level.
The second disadvantage of the implant concerns those women who still have a uterus and who need to take progestogen. The raised levels of oestrogen from an implant are eliminated from the body only very slowly, so that even once you have stopped using implants the lining of the womb continues to thicken every month and you need to continue taking progestogen until this stops happening.
Implants come in three different strengths (25, 50 and 100 milligrams); the higher dose lasts longer, and continues to relieve severe symptoms longer.