Background of Use in Women

Early scientific evidence showing that testosterone is the libido enhancing hormone in the human female was reported during the 1940’s and 50’s.

It was in the mid-1970’s that the vital role of the ovary in testosterone production was established. Subsequent research has established that sexual function declines following oophorectomy. Additional research has established that administration of exogenous testosterone reverses this decline in sexuality.

Prior to 2000 the majority of reported research conducted with exogenous testosterone in women had centered on testosterone implants and injections. While therapeutically effective, these dose forms have significant shortcomings when used in women.

They produce extreme supraphysiological serum levels in women even when administered in reduced doses and have the potential for causing significant side effects including masculisation, hirsutism, acne and voice changes.

Many peri-menopausal women present to their clinician complaining of typical menopausal symptoms such as hot flushes, insomnia, aches and pains, poor libido and vaginal dryness and are treated with hormone replacement therapy (HRT) typically a combination of oestrogen and progestin.

This treatment is very effective for symptoms such as hot flushes and vaginal dryness but usually does not effect libido. Paradoxically this treatment may even aggravate the situation by increasing SHBG levels and so lowering free biologically active testosterone levels.

Many women who suffer from loss of libido date their problem to removal of their ovaries. Bilateral salpingo-oophorectomy, in both pre and postmenopausal women results in an immediate 50% reduction in circulating serum testosterone levels. Oophorectomy in postmenopausal women results in an approximately 30% fall in circulating androstenedione levels.

Oestrogen therapy usually does not restore libido and commonly in this situation, combined oestrogen and testosterone implants are used. Randomized trials comparing oestrogen alone with oestrogen plus testosterone by implant have shown a significant improvement in energy and libido with the combined treatment without an adverse effect on lipids or androgenic side-effects such as excess hair.

Trials have also shown that the addition of testosterone has an additive effect on bone density when combined with oestrogen.

Despite the fact that no testosterone product has been approved in the USA or Europe for the treatment of poor libido in women, male approved testosterone products are usually given in reduced doses (after standard HRT therapy is given for at least a couple of months).

The two most popular products are injectable testosterone (typically Sustanon® 50 mg monthly) or testosterone implants.

There are no published trials using injectable Sustanon in this way, but the practice is common place around the world - a practice called "off-label" usage. Typically two or three injections of Sustanon improve energy and libido, the patient is then offered testosterone implants (50 to 100 mg dosage) every 6 months, in conjunction with HRT. The situation is Australia is somewhat different with a 1% testosterone cream (Andro-Feme®, Lawley Pharmaceuticals) available for use in women.

Insertion of testosterone implants requires a minor surgical procedure which typically involves the use of 5 cc’s of local anaesthetic, a small incision (about 1 cm) and the use of a trocar to insert the implant deep into the fat tissue.

About 10% of testosterone implants are expelled and there is small risk of infection. Current clinical practice does not encourage the long-term use of injectable testosterone, as it has been noted that some patients have developed significant excess hair using injectables typically in a dosage of at least 100 mg Sustanon monthly for at least 6 months.

injectables tend to produce high peak levels but are a useful form of testosterone therapy as an initial ‘trial’ to monitor patient response to testosterone therapy.

Since 2000 there has been significant number of testosterone delivery systems developed, trialled and utilised in clinical practice in testosterone deficient females.

The transdermal testosterone patch, Intrinsa® (Proctor and Gamble, USA) and the topical testosterone cream (Andro-Feme®, Lawley Pharmaceuticals, Australia) lead the way in this exciting area of female healthcare.