259 - Women's sexual health: Why it matters, what can go wrong, and how to fix it

KEYPOINTS

• 01

  Women's sexual medicine is a tiny field relative to the need

  Sharon Parish has practised sexual medicine for about 30 years. She estimates the field's main annual meeting draws 500–600 people, which is probably most of the clinicians who work in it. By contrast, she jokes that the roughly 20,000 urologists at the main urology meeting all think they could handle a man's sexual problem. In the large PRESIDE survey (31,000 women aged 18–99), distressing low desire affected about 10–15% and distressing orgasm problems about 3–6%.

• 02

  Sexual function is linked to vascular and metabolic health

  Peter treats erectile problems in men with prediabetes, for example an A1c of 5.9, as an early warning of blood-vessel disease. Parish says the 'female genital vascular district' may play a similar role in women and be a window into small-vessel disease, though the evidence is still being gathered. Metabolic syndrome, diabetes and obesity are associated with poorer sexual function in women too.

• 03

  Desire and arousal are different, and desire often follows arousal

  Using Rosemary Basson's circular model, Parish explains that many women in long relationships don't feel spontaneous desire. Instead they start from neutral, and desire builds once arousal begins. Her first case, a married mother of two in her late 30s or early 40s who loves her partner but 'doesn't want to have sex', needs a full history covering sleep, stress, relationship, mood, menstrual and gynecologic history, and medications before any drug is considered.

• 04

  Antidepressants are a major, dose-dependent cause

  About 30–40% of people on SSRIs or SNRIs develop treatment-emergent sexual dysfunction. Venlafaxine acts mostly like an SSRI at low doses (up to about 75 mg) and like an SNRI above about 100–150 mg. Parish says the best data for the fewest sexual side effects is for vilazodone, though the drug has its own drawbacks.

• 05

  Birth control pills can lower desire by raising SHBG

  Every woman on combined oral contraceptives has a higher SHBG level, which binds testosterone. Ultra-low-dose (20 µg) pills are more strongly implicated than 35 µg pills. Claudia Panzer's study found that six months after stopping, former users' SHBG levels were still between those of current users and never-users. Parish wants informed consent about this before prescribing the pill, and often suggests switching to an IUD.

• 06

  Testosterone matters for women's desire, and the evidence is substantial

  Women's testosterone at 18–24 roughly halves by the late 30s or early 40s, then levels off. A 2019 Lancet meta-analysis of 46 studies, 36 of them randomized, covering about 8,500 women, supports testosterone for low desire in postmenopausal women. A 300 µg patch (Intrinsa) raised testosterone and improved sexual function without worrying side effects, yet the FDA didn't approve it. Australia has an approved product, through Susan Davis's work.

• 07

  US women must improvise testosterone dosing off-label

  Parish treats the syndrome, hypoactive sexual desire disorder, not a lab number. She checks baseline testosterone to rule out high levels and aims for physiological reproductive-age levels, about one-tenth of a male dose. In practice that means a roughly $200 tube of 1% gel divided into 10 piles, with blood levels checked after 3–4 weeks. She calls this 'not the kind of medicine I want to practice'.

• 08

  Two FDA-approved drugs exist for premenopausal women with low desire

  Flibanserin is a daily 100 mg pill taken at bedtime that acts on serotonin and dopamine receptors. It carries an alcohol warning that has since been relaxed, and works in about 4 weeks (allow 8–12). Bremelanotide is a self-injected auto-injector used about 45 minutes before sex. About 40% of users get transient nausea on the first doses, it causes small rises in blood pressure, and rarely (about 1%) it causes focal hyperpigmentation, so she suggests no more than four doses a month.

• 09

  Orgasm problems are usually about knowledge and technique

  Parish's rough split: about 30% of women reach orgasm through clitoral stimulation, about 30% through vaginal stimulation, and about 30% through either. For a 30-year-old who has never had an orgasm, she starts with education: anatomy, self-exploration, vibrators and communicating with a partner. She points patients to the OMGyes educational site (about $40 for standard programs).

• 10

  The fear of hormone therapy is largely unfounded

  Parish says that even in the Women's Health Initiative, the increase in breast cancer incidence with conjugated equine estrogen plus MPA was only about 0.1% in absolute terms, with no increase in breast cancer deaths over 20+ years. Estrogen alone was associated with fewer breast cancers. Women aged 50–59 differ greatly from older starters. Hormone therapy can cut hot flashes by about 75–80%, and she calls the generation of women denied it a 'real tragedy'.