Whilst doing some research regarding different hormone therapy regimes in the UK, I came across a very interesting publication called "A guide to hormone therapy for trans people" published by the NHS.  I have published an extract below

Taking hormones without a doctor’s prescription, however understandable your reasons, is unwise and could put your health at risk.
What are the risks of taking hormones without a doctor’s prescription?
The principal dangers involved when self-medicating are:

1. the products may not be genuine and may therefore have no effect at all, so you may be wasting your money
2. the products may be of poor quality and may even be harmful
3. you may not have a thorough picture of the possible risks and side effects
4. you may not have thought about the consequences of combining hormones with any other medication or herbal products that you might be taking
5. you won’t have had a health check to see if you have any other conditions that could be affected by hormone medication the dosage and the way in which you are taking the medication (pills rather than patches, for instance) may not be suitable for you.

• 
  If you have already started taking hormones in this way, you should see your GP and/or a gender specialist as soon as you can. The doctor should bring you into a properly prescribed regime as quickly as possible.

Summary of information about hormone medication
You are strongly advised to get a doctor’s prescription for your hormones. If you do have a valid prescription from your doctor, the medication is readily available from any high street chemist. You may find it more convenient to buy your medication through one of the internet sites endorsed by the NHS, for example http://prescriptions.pharmacy2u.co.uk/user/default.asp
Although the risks are low when you are taking prescribed hormones, as with all medication there can be some unwanted side effects. These will vary from person to person and will depend on the specific medication you are prescribed. Your doctor should make you aware of these.

Trans women
Feminising medication

Oestrogen

• Oestradiol-based formulations are naturally occurring oestrogen (17ß oestradiol). They include:
  – oestradiol patches (best for those over 40, smokers or those with circulatory problems; least risk)
  – oestradiol gel (applied to skin; also low risk) – oestradiol/oestradiol valerate (taken in pill form; some risk)
• conjugated equine oestrogen (from mares’ urine; taken in pill form; more risk. Some people regard the method of collection from horses as unethical)
• ethinylestradiol (not recommended; taken in pill form; most risk of side effects)

Medication to reduce testosterone effects
This treatment will not be necessary in all cases. All these products are effective and each will be suitable for some service users.

• Cyproterone acetate is preferred by some service users because it is in pill form and is therefore easily administered. It works by blocking testosterone receptors, and it is effective against androgen (testosterone) produced by the adrenal glands, as well as that produced by the testes. Heavy alcohol use reduces its effectiveness.
• Spironolactone (taken in pill form) is a well-tolerated andeffective anti-androgen.
• Goserelin or leuprorelin is administered by subcutaneous (under the skin) depot injection. It is preferred by some doctors because it is believed to have fewer side effects. It does not block testosterone produced by the adrenal glands, but this is not essential.
• Finasteride (taken in pill form) reduces the effect of male hormones and promotes a modest regrowth of hair on the head if the hair follicles have not been inactive for too long. It is not possible to reverse significant hair loss.

Progesterone is not usually prescribed for this condition. It increases the risk of thrombosis and other side effects. Although it can reduce the effect of testosterone if taken in high doses, it can also, paradoxically, inhibit the action of oestrogen and may therefore have anti-feminising effects, such as increasing libido and causing facial hair regrowth.

Taken from the NHS Guide for Medical Practitioners - A guide to hormone therapy for trans people

http://tinyurl.com/65j8wpx

Thanx for this Carol. I've printed it off and read it thoroughly. Very useful document. Confirms much of what I already knew, but adds some more info too. Good to see that the NHS has such info available to them, especially as I've just started to contact them about my GRC! x

You're welcome sweetheart

xxx