Like lava rising from a volcano, the heat streams across your body, reddening your face and quickening your heart. Suddenly it feels as if every pore in your skin has begun to sweat. If you're lucky, the hot flash subsides as quickly as it began. If you're not… Well, some women can remain in the broiler room for up to five minutes per flash.
Hot flashes - and the night sweats they produce - will plague some 80 percent of people transitioning to menopause, defined as the lack of a menstrual period for 12 consecutive months, said Dr Stephanie Faubion, director of the Mayo Clinic's Center for Women's Health in Jacksonville, Florida, and medical director for the North American Menopause Society.
Hormone replacement therapy, also called HRT, is still the preferred choice of treatment for menopausal symptoms - which can include hot flashes, chills, night sweats, sleep problems, mood changes, vaginal dryness and pain during sex.
"However, some women are not good candidates for hormone therapy because of contraindications, such as a personal or strong family history of oestrogen-dependent cancers, cardiovascular disease, stroke, blood clotting disorders, deep venous thrombosis and chronic liver disease," said Dr Chrisandra Shufelt, professor and associate director of the Women's Health Research Center at Mayo Clinic in Jacksonville, Florida.
"And some women have a personal preference not to take HRT. For all of these women, we want to provide evidence-based guidance on alternate methods to help manage their hot flashes," said Shufelt, chair of an advisory council that produced the "2023 Nonhormone Therapy Position Statement" of the North American Menopause Society.
That guidance, published Monday in the journal Menopause, updates an older 2015 position statement. For the 2023 update, experts evaluated the latest studies on nonhormone medical, herbal and behavioural therapy and lifestyle approaches for vasomotor symptoms - the medical term for hot flashes.
"Specifically, what we're talking about are hot flashes and the accompanying night sweats because those are the most common," Faubion said. "We're not talking about depression, sleep or anxiety symptoms in these guidelines."
Not only do the vast majority of women experience hot flashes, for a third of women they can last more than 10 years, Shufelt said.
New FDA-approved drug available
The most exciting addition to the guidelines - so new it had to be inserted just before publication - is a non-hormonal medication recently approved by the FDA called fezolinetant, which is available by prescription, Shufelt said.
"This is the first-of-its-kind medication, a neurokinin 3 (NK3) receptor antagonist, that tackles moderate to severe hot flashes where they begin - the brain," she said.
Fezolinetant, which goes by the brand name Veozah, "targets the neural activity which causes hot flashes during menopause. It works by binding to and blocking the activities of the NK3 receptor, which plays a role in the brain's regulation of body temperature," the FDA said in a statement announcing the drug's approval.
"It's really exciting because 10 years ago we were not talking about the aetiology (cause) of hot flashes because we didn't really know too much about it," Faubion said. "Now we know that blocking the KNDy (pronounced candy) neurons in the brain - kisspeptin, neurokinin B and dynorphin - reduces hot flashes, so we know we're in the right neural pathway."
Nausea and headache are the most common side effects of fezolinetant, she added, but overall, the new drug "seems to be very well tolerated."
The only other FDA-approved non-hormonal medication has been a low-dose version of an antidepressant SSRI, or selective serotonin reuptake inhibitor, designed to treat depression by increasing the amount of a feel-good hormone called serotonin in the brain.
Other good non-hormonal options
The guidance also found credible evidence that cognitive behavioural therapy, clinical hypnosis, antidepressants, weight loss and the anticonvulsant drug gabapentin, which is also prescribed for nerve pain, can help reduce hot flashes.
An overactive bladder drug, oxybutynin, also "profoundly dropped hot flashes," Shufelt said. "Many non-hormonal treatments have been discovered inadvertently while being used for other reasons, and then women self-report their hot flashes have improved."
None of these drugs are on demand, Shufelt said, "meaning you can't just use these when you have a hot flash. They're meant to be taken daily, long-term, and some of them can take up to three months before you will see a really effective onset of improvement.
"You've got to give it that full time," she added. "You can't take it for one or two weeks and say 'Oh, it's not working. I've got to stop doing this.' It's also important to be cautious about taking these drugs with other medications. You need to work with a menopause-certified provider."
Non-hormonal treatments that aren't backed by evidence
A variety of treatments did not have enough supporting scientific evidence to recommend their use, Shufelt said. Use of cannabinoids such as delta-9-tetrahydrocannabinol (THC) does not work, according to the guidelines. Nor do over-the-counter supplements and herbal remedies or soy products.
The committee found no proof that acupuncture and chiropractic manipulations were of any help, either. Two medications that used to be recommended - the anticonvulsant pregabalin and a blood pressure drug called clonidine - were taken off the approved list, as additional studies have found significant side effects associated with using them, Shufelt said.
Several lifestyle improvements, such as paced deep breathing, cooling techniques, exercise, yoga, relaxation, mindfulness, dietary modification and avoiding triggers were also lumped into the unapproved list of treatments.
But that's because they have seldom or never been studied, not necessarily because they don't work, Faubion said.
"You know, we don't do studies about understanding the health impact of jumping out of an airplane without a parachute, so just because there are no studies doesn't necessarily mean they don't work," Faubion said.
"Take avoiding triggers: If caffeine or alcohol or smoking - which we shouldn't do anyway - trigger a hot flash and avoiding those help, great. That's common sense. And obviously we should all exercise, eat a healthy diet and reduce stress," she said.
Studies did show that weight loss reduces hot flashes, as do mindfulness practices such as cognitive behavioural therapy, Shufelt said.
"That's a mind-body technique that you could also incorporate and say, 'Yes, that's a relaxation technique or that's a biofeedback kind of mechanism that can change the brain,'" she said.
"Look, if somebody tells me, 'I avoid caffeine in the morning and I don't have my afternoon hot flash,' I'm going to tell them to continue to do that. Just because the science didn't show it in a large study doesn't mean that it might not work individually, for you," she said. "Just be sure it's a quote 'no harm no foul' situation."