Women are posing as men to buy testosterone from online pharmacies because of difficulties getting NHS prescriptions in Wales, according to a consultant.
There has been a "very sharp increase" in testosterone referrals to the NHS for post-menopausal women, but access varies between health boards.
Menopause specialist Dr Michelle Olver said she had seen women with up to 12 times the safe level of the hormone - risking permanent side effects - because they have bought online.
She would like to see an equitable all-Wales approach to testosterone prescribing, with it used to help with things such as libido.
The Welsh government said: "All health boards are expected to provide individualised care."
While testosterone is proven to help with libido after menopause, many women also claim it helps with energy levels and cognition.
Olver, a consultant in sexual and reproductive health, said it was "incredibly sad" to see women lying to get hold of the drug online, because they were being "denied access to something they need", but urged proper counselling and monitoring was needed.
"We want to maintain women in female physiological range for testosterone. We don't want them to have sky-high levels," she said.
"When you persistently have very high testosterone levels you can get undesirable permanent side effects.
"Nobody wants to have baldness, deepening of the voice or enlargement of the clitoris."
Emma Thomas co-founded menopause support group Menopals Cardiff and Vale, and said many members had spoken of their struggles to access the hormone on the NHS.
"We hear a lot of women saying their GP thinks there's no need for it or their surgery won't prescribe it," she added.
The 59-year-old from Sully, Vale of Glamorgan, said she noticed a shift in her own outlook at 47, when she went from a "really sociable, happy person" to someone who felt "quite insecure, paranoid, low in mood".
"I'd sort of lost my joy."
She felt Hormone Replacement Therapy made a difference within 10 days of starting it.
Once the dosage and type of HRT was stable, she was prescribed testosterone by her GP.
She added it took around six months to notice an effect, saying: "It was the final piece of the puzzle for me.
"I feel like my old self - I've got a zest for life."
Specialists and women who have tried testosterone agree it was not a "silver bullet" and would not be appropriate for everyone.
Emma Jones, 57, said within a week of taking the drug she noticed her energy levels increase but also felt "jittery and on edge".
"I felt like I'd changed into the body of an 18-year-old, thinking about sex from the moment I woke up," she laughed.
However, Jones felt strongly that women should be able to access different types of HRT to see what works for them.
BBC Wales spoke to one woman who was prescribed testosterone by her NHS GP, but when she moved to a neighbouring health board area her new GP surgery refused to continue the prescriptions.
She paid for a private consultation, prescription and blood tests, but when her levels of testosterone were stable, she filled in a questionnaire for an online pharmacy pretending to be a man to get the hormone for a fraction of the cost.
Olver runs the menopause clinic at Aneurin Bevan's health board and said "we have definitely seen a very sharp increase in testosterone referrals from primary care - for women wanting to access it".
"It is difficult to meet demand and we have a testosterone clinic set up now for women who want to trial it."
She said each of the seven health boards in Wales used a traffic light system - some are red, meaning only specialists can prescribe the drug.
There are two amber options - one involves a GP requesting the support or agreement from a hospital specialist that testosterone is appropriate for a patient.
The second requires the hospital specialist to start and monitor the prescription with a "shared care agreement", with GP's continuing to prescribe it.
"One of the main reasons for this disparity is because we don't have a licenced product for woman on the NHS," Olver said.
A female testosterone product has been available in other countries for many years, and is available from private clinics across the UK.
Olver said it had now achieved a licence in the UK but still needed to be appraised by NICE to determine if it was cost-effective to use in the NHS, at which point discussions would also be required with the pharmaceutical industry about the cost to the NHS.
Currently the female product, Androfeme, costs the NHS around £100, but the male product, Testogel, is £30.
"Studies show about 60% of women will find benefit in improving their libido," said Olver.
"It's really important to manage expectations, because it's not this wonder drug that sometimes it's made out to be on social media.
"There's lots of reasons why women don't want to be intimate - some of those will be external factors, some will be anatomical.
"So it's really important to be fully counselled on what to expect when using testosterone, but also the limitations of its use."
The Welsh government said: "All health boards are expected to adhere to the NICE guidelines on identification and management of menopause including providing individualised care when prescribing HRT.
"We are aware this may include some practitioners prescribing testosterone for some women.
"We expect all health boards to conform to any recommendation made by NICE in relation to prescribing testosterone when its guidance is published."
