“Replacing the oestrogen that your body is no longer producing with the versions found in conventional HRT is like replacing parts designed for a Chevvy with those made for a Mercedes,” says Dr Jonathan Wright, Medical Director of Tahoma Clinic in Washington USA, and a long-time advocate of what are known as bio-identical hormones. “They may be roughly the same, but with both engine parts and biology, very precise measurement matter.”
The idea of bio-identical hormones has been attracting a lot of attention in America, especially since actress Suzanne Somers, previously best known for her role as a ditzy blonde in the 1980s sitcom hit Three’s Company, published a best-seller on their benefits. However claims that they are safer or more effective has been dismissed as “marketing” by the American drugs authority, the FDA. Here in the UK, the situation is typically much more low-key.
What are bioidentical hormones?
There’s been far less publicity about them, although a small but growing number of women have been taking them. Several brands are available on the NHS, however most GPs are reluctant to prescribe them, saying there is no evidence they work. So what exactly does it mean to say that a hormone is bio-identical? A regular HRT pill contains oestrogen – the hormone that promotes growth so it’s good for skin and hair, lifts depression, controls hot flashes – along with a synthetic progesterone (a progestogen/progestin).
Not all oestrogens are equal Just to complicate matters oestrogen in the body comes in three varieties – oestrodial, oestrone and oestriol. Not only that but they come in very different proportions. Oestriol is the weakest and pre-menopausal women normally have lots of it; it makes up about 90 per cent of the total amount.
The next most abundant is oestradiol, the most potent one, at around 7 per cent, followed by oestrone at 3 per cent. But in regular HRT, the oestrogen part doesn’t come in anything like those proportions. One of the most common brands is one called Premarin which actually comes from the urine of pregnant mares. Not only are the proportions very different but it also contains extra horse oestrogens. Oestrone shoots up from being the least to the most abundant at 75 per cent; next comes oestradiol which, together with two other horse oestrogens, makes up between 6 and 15 per cent. And finally you get 5 to 19 per cent of another horse hormone called equilin. Very different.
Even in hormones which are molecularly very similar, the difference in effect can be huge. One way of summing up the difference between men and women would be that it is the difference between early exposure to testosterone or oestrogen. But as these below pictures show, the oestrogen oestrodial is actually more like testosterone than it is like Premarin. Yet women are advised that premarin is a suitable replacement for oestrogen.
Why progesterone is key
The other hormone that’s found in regular HRT is called a progestagen, or sometimes a progestin. These are non-identical versions of the hormone progesterone. During menopause the amount of progesterone in your body drops more dramatically than oestrogen, to almost zero. Non-identical progestin is added to regular HRT to reduce the risk of womb cancer which is raised by giving oestrogen on its own. You can get an idea of how big the difference is between bio-identical progesterone and progestin from their effect on pregnancy. Progesterone is the hormone that the body makes to support pregnancy – it’s used as part of infertility treatments – while progestin raises the risk of congenital abnormalities and miscarriage.
According to NHS Direct, other progestin side effects include breast tenderness, headaches, mood-swings and depression. The main side-effect of progesterone is sleepiness.
Examining the evidence
So are the identical versions of these hormones safer and more effective? It’s an attractive idea that makes sense but what’s the evidence? At the moment if you want it proved in a big trial comparing the two, then it’s not there. But there are plenty of people who find that, quite apart from the possible long-term risks of regular HRT, that it just doesn’t agree with them, while a switch to bio-identical HRT (BHRT) transforms them. But this approach gets very little support from most NHS GPs, who may point to a few small studies that have found no benefit from using progesterone.
The official advice is that providing you have as low as possible a dose of regular HRT and don’t stay on it for any longer than five years, your risks of any problems are very low. “There is absolutely no evidence that bio-identical hormones are any safer,” declares Dr Sarah Jarvis, speaking for the Royal College of GPs. But the official view of the Royal College would be thought curious in France, where both progestins and progesterone are widely used. Because of this, there is much more research done on the difference between them. Here in the UK, progestins are only included in HRT to stop cancer developing in the lining of the womb.
But French studies suggest that progesterone has all sorts of other benefits, almost none of which come from progestins.
Call for more research
Now evidence like this doesn’t completely prove the case for bio-identical hormones and everyone agrees there needs to be more research. So will the big trials that doctors are demanding now be run? The depressing truth is that it’s unlikely without strong consumer pressure. Calls for such research are not new. Thirty years ago an editorial in the Journal of the American Medical Association asked how long clinicians will have to wait for proper clinical trials on the benefits of oestriol, the weakest of the oestrogens. “Enough evidence has been accumulated,” it said “that we may say that it is safer than oestrone and oestradiol.” The trials have still not been done.
If you are unwilling to wait and HRT isn’t working for you, what can you do? You can ask your GP as some are prescribing bioidentical hormones as unlicensed medicines on the NHS or go to a private doctor who specialises in such hormones. The option most women use is to decide on the basis of their symptoms and use a bioidentical transdermal cream they can obtain for themselves. Wellsprings has two: Serenity with just progesterone and 20-1 a combined progesterone and oestrogen natural HRT replacement.