1. Women produce more testosterone than estrogen, but far less than men do. It is derived in equal amounts from the adrenals and ovarian stroma.
2. Testosterone acts as a central neurosteroid affecting interest in sex.
3. Genital sexual response in women requires the tissues to be oestrogenised though androgens may also have a role.
4. Ovarian removal or ablation by radiotherapy, infarction or infection will result in depletion of testosterone. This may affect sexual function in some women. This can only be assessed once oestrogen has been adequately replaced both vaginally and systemically.
5. A total testosterone level in not very informative as testosterone is significantly protein bound. Measure the sex hormone binding globulin and calculate a Free Androgen Index.
6. If a woman complains specifically about loss of sexual interest ask if there are other associated symptoms of androgen deficiency such as lack of motivation or energy, myalgiaor mood change (often anxiety):
If the free androgen index is in the lower quartile for women,
That she is adequately oestrogenised (preferably with a non-oral estrogen) so there are no flushes
That atrophy has been reversed so sex is comfortable
There are no relationship issues
You can then consider supplementation as suggested by NICE NG23.
7. There are no licensed testosterone products for women on the UK market.
The most suitable options to offer if supplementation is appropriate are either
- Tostran® – 2% testosterone gel. This is licensed for use in men. It delivers 10mcg per 0.5ml metered dose. The typical starting strategy is one measure applied every other day to the thigh. This delivers an average 5mg/day
- Testogel ® – 1% testosterone gel in sachets. This is licensed for use in men. It delivers 50mcg per 5ml sachet. This is too big a dose to use at once so advise women to start with 1/10 sachet = 5mg daily. They should eke the sachet out over 10 days rolling the top and sealing with a clip between uses. Apply to the thigh. Do not prescribe the pump version as the concentration is higher and the dose delivered per pump measure is 20.25mg and this cannot easily be fractionated.
- AndroFeme1 – 1% testosterone cream. This is produced and licensed in western Australia but can be made available on a private prescription in the UK. It is imported and supplied by Clinigen, who produce guidance which is consistent with the information above. The pharmacist can only obtain a supply from them. The typical starting strategy is 0.5ml = 5mg testosterone applied daily to the thigh.
8. We suggest checking the free androgen index after about 8 weeks and reviewing clinically and biochemically.
9. Patient satisfaction is the primary criterion with the free androgen index somewhere near or just above the female median. This will avoid excess hair or acne though the site of application may have increased hair growth due to higher local concentration.
10. If no better after three months and blood levels have increased, stop.