Calroy Health Sciences

 Perimenopause symptoms keep changing for multiple reasons. One being that the hormones behind them do not decline in a straight line. During perimenopause, estrogen rises and falls unevenly from cycle to cycle, so a month of broken sleep can give way to a stretch of hot flashes, then a season of brain fog or skin that suddenly behaves differently. For most women, this transition lasts about four years on average and up to 10 years, according to the U.S. Office on Women’s Health.

Why do symptoms shift from one month to the next?

In the years before menopause, the ovaries no longer follow a predictable pattern. Some cycles release an egg and others do not, and cycle length can stretch or shorten without warning. Because the body makes progesterone after an egg is released, in cycles without ovulation progesterone barely rises. The lack of progesterone leaves estrogen unbalanced for part of the cycle, which is one reason the same woman can feel noticeably different from one month to another. 

Estrogen also helps maintain bone health and density. As estrogen levels decline through the transition and remain low after menopause, bone density becomes a longer-term priority. Many women overlook bone health because in early stages it is unnoticeable.

Most women first notice changes such as irregular periods in their 40s, though some notice them in their 30s and others not until their 50s, according to Mayo Clinic. How the changes arrive varies as well. The Office on Women’s Health notes that symptoms may begin suddenly or mildly and may come often or only once in a while.

Because early signs appear well before menopause and may come and go, many women do not connect them to perimenopause at first.

What are the stages of menopause, and how long does each last?

Menopause unfolds in three key stages: perimenopause, menopause and postmenopause. Perimenopause, the stage with the most change, has early and late phases of its own. Mayo Clinic defines early perimenopause as a time when cycle length begins to vary by seven days or more, and late perimenopause as a time when 60 days or more can pass between periods. 

By the end of perimenopause, hormone levels have fallen to very low levels, while during the early phases estrogen rises and falls unpredictably. This helps explain why the first year of perimenopause can look and feel very different from the last.

Sources: U.S. Office on Women’s Health, Menopause Basics (updated Oct. 19, 2026); Mayo Clinic, Perimenopause.

Because menopause can only be confirmed after a full year without a period, many women confuse perimenopause with menopause. Most of the symptoms associated with menopause happen in the perimenopause phase.

What mistakes make changing symptoms harder to read?

Assuming changes are due to stress or normal life circumstances. Because many women in their 40s live full lives with many responsibilities at home and in their careers, it can be easy to assume sleep issues or brain fog are simply due to stress. You know your body best. If you are in your early 40s through 50s and are experiencing changes to your cycle or that make you feel less like yourself, speak to your doctor about perimenopause.

Counting on one blood test. Hormone levels shift so often during perimenopause that a single blood test offers a snapshot, one that may not reflect what is happening over weeks or months. During perimenopause, a blood test may show perfect estrogen levels one day, elevated estrogen the next, and very low levels on the same day in an upcoming cycle. Providers usually look at age, changes in the menstrual cycle and the pattern of what a woman notices, combined with blood tests.

Measuring yourself against someone else’s timeline. Perimenopause starts at different ages for everyone, and the transition period can vary widely from woman to woman. Hearing the experiences of family members or friends can be helpful benchmarks, but every person’s experience with the timing of perimenopause and menopause will be unique.

Adding multiple products at a time without a full review. Each new product brings its own ingredients and doses, and overlap is easy to miss. Adding supports one at a time can help determine what is working. A woman should share the full ingredient list with her provider or pharmacist before starting any dietary supplement.

Where do symptom-specific care and upstream support fit?

Both have a place. Most approaches address symptoms one at a time as they appear. Newer approaches support the underlying system: the gut-hormone-bone axis through which estrogen decline makes its widest impact.

Support aimed at one concern, such as a sleep plan or specific formula for hot flashes, makes sense when one symptom is causing most of the disruption. Some women also want foundational support for the upstream inflection point through which estrogen decline makes its widest impact,, because the specific concerns keep changing. These are different goals, and many women pursue both.

Calroy Health Sciences formulated Selentra HP™ around that upstream inflection point.

“What a woman feels during the transition is only part of what is happening,” said Dr. Lauren Lattanza, NMD, a naturopathic physician who works with Calroy Health Sciences on healthcare education. “As estrogen declines, gut barrier function, immune balance and bone health all shift, often well before a woman notices symptoms. That is why daily support for the upstream inflection point makes sense for the length of the transition.”

How should you judge a supplement made for the menopause transition?

Five questions can help a woman and her provider decide whether a supplement fits this stage of life.

1. Was it studied in women like me? Research is most useful when the participants resemble the woman reading the label. Look for studies that enrolled perimenopausal or postmenopausal women and report their ages and menopausal stage. The details of the study design add context too, including how long it ran, whether it compared the product with a placebo and whether it tested the finished formula or individual ingredients. The dose used in the research should also match the dose in each serving.

2. What is the formula designed to target? Some supplements focus on a single concern, such as hot flashes or sleep. Others are built around a specific system in the body, and some are marketed broadly as menopause support.

3. Is it hormone-free, and can it be taken with menopausal hormone therapy (MHT)? The label should state whether the product contains hormones. Women using MHT will want to confirm that a supplement can be taken alongside it. Women who cannot use MHT, or who choose not to, may be looking specifically for a hormone-free option.

4. What are its manufacturing and quality standards? Every supplement sold in the U.S. must be made under current Good Manufacturing Practices (cGMP), which set the legal baseline. Third-party testing by an independent lab goes further, confirming that a product contains the ingredients on its label in the stated amounts. 

5. Has a healthcare provider reviewed it? A provider can weigh a supplement against a woman’s health history, current medications and the other products she takes. 

Where does hormone therapy fit?

Whether to use menopausal hormone therapy MHT is a decision a woman makes with her provider, based on her health history, needs and preferences. Some women use it through the transition, some cannot for medical reasons and others choose not to use it at all. 

Each situation shapes which supplements make sense. Whether or not you are taking MHT, check with your healthcare provider to ensure a supplement is the right fit for you. 

How is Selentra HP built for the transition?

Selentra HP supports the biological foundation of the menopause transition, and women’s midlife health.* It is powered by two clinically studied, patented ingredients, each supported by published, peer-reviewed clinical studies conducted in peri- and postmenopausal women, the population this formula was designed for. Selentra HP is hormone-free, and can be used with or without MHT.

Selentra HP™ combines two ingredients, each studied separately in women in menopause or perimenopause:

• VMK223™, a postbiotic from Bifidobacterium breve BB091109. In women ages 40 to 55, taking VMK223 daily for 12 weeks was associated with lower levels of the inflammatory markers CRP and IL-6 than placebo, according to a randomized, placebo-controlled trial published in Frontiers in Microbiology. 

• A second 12-week, placebo-controlled trial in the same age group, published in Dermatology and Therapy, tracked skin changes from each woman’s starting measurements. Hydration rose 28%, elasticity rose 27% and wrinkle depth fell 28% in the VMK223 group, compared with an 11% rise in hydration, a 6% rise in elasticity and a 4% drop in wrinkle depth with placebo.

• OsteoCaf™, a patented extract of Dalbergia sissoo leaves. Postmenopausal women with low bone density who took 600 mg of OsteoCaf daily for one year, along with calcium and vitamin D, maintained stable bone mineral density at most measured sites, according to an open-label study published in the Journal of Mid-life Health.

Learn about all three studies on the Selentra HP page.

Selentra HP supports a healthy inflammatory response during menopause, metabolic resilience during hormonal change, helps maintain healthy bone density and structure, and promotes skin health and connective tissue integrity.* The daily serving is two capsules, one in the morning and one in the evening.

Every batch of Selentra HP is produced under Calroy’s Total Quality System, in compliance with FDA-defined cGMP, and is third-party tested by an independent lab. Calroy maintains batch and test records for each lot.

What should you do when your symptoms change?

A simple record of what has changed over the past few months, including when each change started and how often it happens, gives a woman and her provider a clearer picture. Sleep, mood, temperature regulation, skin health, focus and cycle length are all worth noting. She should bring the record to her next appointment and point out symptoms that seem new or different. A woman considering a supplement can evaluate it with her healthcare provider using the questions above.

Frequently Asked Questions

Is it normal for perimenopause changes to disappear for months and then come back?

Yes. Because ovulation does not happen every month during perimenopause, periods or symptoms might stop for a few months and then start up again, according to the Office on Women’s Health. Hot flashes, sleep trouble or other changes can lessen and then return weeks or months later. A quiet stretch does not necessarily mean perimenopause is over. Perimenopause is only complete once menopause has been confirmed. Menopause is generally confirmed after 12 consecutive months without a period. Until then, keep noting what changes and when.

Can you still get pregnant during perimenopause?

Yes. Ovulation becomes irregular during perimenopause but does not stop until menopause, so pregnancy is still possible even when periods are months apart. The Office on Women’s Health advises continuing birth control until one full year after your last period if you do not want to become pregnant. If you use hormonal birth control, it can hide your natural cycle, so ask your provider when it makes sense to stop.

Why do perimenopause symptoms feel worse right before my period?

Hormone levels go up and down unpredictably during perimenopause, and in some cycles the swing is sharper than it was prior to starting perimenopause. That can make the days before a period harder than they were in your 30s. Tracking these changes can show whether the pattern follows your cycle. If the premenstrual stretch is disrupting work or relationships, a provider can help.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.