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RegenHRT: Physician-Guided Hormone Therapy
A personalized medical approach to restoring hormone balance and protecting long-term health.
RegenHRT is RegenCen's proprietary approach to bioidentical hormone replacement therapy. Developed and led by Dr. Gustav Lo, MD — a primary care physician with more than 30 years of clinical experience — RegenHRT is built on a simple but often overlooked principle: hormone therapy done right isn't just about symptom relief. It's about restoring your body to where it used to be, and keeping it there.
RegenHRT at a Glance
Our approach:
Bioidentical hormone replacement therapy
Best for:
Women in perimenopause or menopause, men experiencing fatigue, brain fog & low drive
How we dose:
Individualized — based on labs, medical history, body composition, and life stage
Monitoring:
Lab testing every 3-4 months to confirm physiologic levels
5Who guides your care:
Medically licensed, menopause-certified providers trained & led by Dr. Gustav Lo, MD — 35+ years practicing medicine
Target:
Physiologic hormone levels — not just symptom relief
Why symptom relief isn’t enough
Hormones regulate far more than how you feel on any given day. They govern your cardiovascular system, your bones, your brain, your metabolism, and your muscle mass — all the way out to your hair, skin, and nails. When hormone levels fall — whether gradually in your 30s and 40s, or suddenly at menopause — the effects extend well beyond symptoms you can feel.
As RegenCen Chief Medical Officer Dr. Lo often quotes FDA commissioner Marty Makary, MD: “When estrogen vanishes, a cascade of disease and aging begins.”
It's a clinical reality, and it's the reason RegenHRTTM exists.
Conventional hormone therapy has historically focused on one thing: managing symptoms. If hot flashes improve, the treatment is considered successful.
But hot flashes may improve even when hormone levels remain well below the physiologic range — the range your body actually needs to protect your heart, your bones, and your brain. Symptom relief and disease prevention are not the same target, and treating them as if they are means most patients are being under-treated without knowing it.
RegenHRT is built around physiologic levels — not the lowest dose that quiets symptoms, but the levels that support the systems hormones were always meant to protect.
Not all hormone therapy is the same, and the difference starts with what's actually being prescribed.
Bioidentical hormones are structurally identical, atom for atom, to the hormones your body produces naturally. They're derived from plant sources and chemically modified to be an exact match for human estrogen, progesterone, and testosterone. Your body can't distinguish them from what it makes itself — because there is no distinction.
Synthetic hormones, by contrast, are manufactured compounds that are similar to your natural hormones but not identical. The most well-known example is Premarin (conjugated equine estrogens named for their source: pregnant mare urine) which was the standard of care for decades and the basis for the 2002 Women's Health Initiative study that caused widespread fear of hormone therapy. That study combined non-bioidentical estrogen with a synthetic progestin called medroxyprogesterone. It was that combination — not bioidentical hormones — that increased breast cancer risk.
When the research is redone using bioidentical hormones, the risk profile changes substantially. Bioidentical estradiol and progesterone therapy does not carry the same cancer risk as the synthetic hormones studied in 2002 - in fact, several modern studies using natural progesterone and estradiol show no increased breast cancer risk at all. This is well-established in the literature, even if it hasn't fully reached mainstream medical practice.
RegenHRT uses bioidentical hormones exclusively — estradiol, progesterone, and testosterone that your body recognizes as its own. This is the foundation everything else is built on.
A closer look at bioidentical hormones: the molecular difference explained
What makes RegenHRT different: the methodology and process
RegenHRT is built on three principles that set it apart from both conventional hormone prescribing and lower-oversight hormone clinics: comprehensive evaluation, individualized dosing, and ongoing monitoring. Together, these comprise our clinical philosophy - not just a cookie-cutter protocol.
Most hormone prescribing starts and ends with one question: are you still having periods? If yes, hormones aren't offered. If no, a standard estradiol and progesterone dose may be prescribed. Testosterone is rarely mentioned.
Symptoms and negative health effects from hormone deficiency usually happen before periods stop. Recent research proves that symptom relief and better health outcomes happen with earlier treatment - before the traditional “no periods for 1 year” rule.
That’s why RegenHRT starts differently. Before any treatment decision is made, we evaluate:
- Current symptoms and how they're affecting your daily life
- Baseline lab values — estrogen, progesterone, testosterone, and other relevant markers
- Medical history and risk factors
- Body composition, including lean mass
- Lifestyle factors that influence how you metabolize hormones
- Patient preferences for delivery method
We want to know where you're starting because that gives us a target to work toward, and because your starting point is different from everyone else's
Every patient's hormonal profile is different. Responses to hormone therapy vary based on metabolism, body composition, baseline levels, age, and life stage. A dose that achieves physiologic levels in one patient may be far too little (or too much) for another. This is true whether we're treating a woman navigating perimenopause or a man experiencing age-related testosterone decline.
RegenHRT uses a proprietary dosing algorithm that accounts for all of these factors to determine a starting dose calibrated to your individual profile. This isn't like picking “big pill or little pill.” It's precision dosing.
Delivery method is also individualized. Options vary by patient and by hormone, and may include:
- Pellet therapy — a small implant placed under the skin that releases hormones steadily over several months
- Topical therapy — creams or gels applied and absorbed through the skin (transdermal delivery)
- Oral progesterone — bioidentical progesterone in pill form (for women; distinct from synthetic progestins)
- Vaginal preparations — for localized tissue treatment, avoiding systemic absorption (for example, in breast cancer survivors)
- Other physician-guided options — depending on individual clinical factors
The right delivery method depends on your clinical picture, your lifestyle, and your preferences — not a default protocol.
Hormone levels change over time. Treatment that isn't monitored isn't really treatment — it's a one-time prescription that may or may not be doing what it needs to do six months from now.
RegenHRT includes regular follow-up lab work — typically every three to four months — to confirm that hormone levels remain within the physiologic range, that symptoms continue to improve, and that dosing is adjusted as your needs evolve.
This is what we mean when we say RegenHRT is long-term medical care rather than a one-time fix.
Step 1: Comprehensive consultation We begin with a full picture — your symptoms, medical history, lifestyle, and goals.
Step 2: Baseline lab testing Blood work establishes your starting hormone levels across estrogen, progesterone, testosterone, and other relevant markers.
Step 3: Personalized treatment plan Unlike other hormone clinics that use cookie-cutter protocols, at RegenCen your dosing and delivery method are selected based on your individual profile.
Step 4: Monitoring and Optimization Follow-up labs at regular intervals ensure your levels stay where they need to be, so you feel your best and age you best. Monitoring is also important for dose adjustments over time.
Hormones as an interconnected system
One of the most common mistakes in hormone therapy is treating a single hormone in isolation. Estrogen gets addressed. Progesterone is added only as an afterthought. Testosterone is overlooked entirely.
Hormones don't work independently, so RegenHRT evaluates the full hormonal system.
Estrogen, progesterone, and testosterone function as an interconnected network. A change in one affects the others. Too much or tool little of one creates downstream effects throughout the body. This is true for women navigating hormonal shifts from 20s through 50s, across perimenopause and menopause — and for men experiencing the slower, quieter testosterone decline.
For women:
Consider progesterone and estrogen: when progesterone drops, which can begin as early as the late 30s, estrogen becomes relatively dominant. That imbalance is experienced as bloating, irritability, heavier periods, weight gain around the midsection, and poor sleep, just to mention a few. The problem isn't estrogen. It's the ratio of estrogen to progesterone.
Testosterone is often the missing piece in women's hormone care. Women actually produce more testosterone over their lifetimes than they do estrogen, five to ten times as much. Testosterone strongly influences energy, strength, motivation, and lean muscle mass. Sex drive can also be profoundly affected. When it drops, the symptoms — tiredness, low drive, loss of strength — are frequently attributed to lifestyle or depression rather than hormones. Most conventional providers don't address it at all.
For men:
Men's hormonal picture is simpler in some ways — testosterone is their dominant sex hormone — but it doesn't operate in isolation. Estrogen plays an important role in men's cardiovascular health, bone density, and brain function. When testosterone declines with age, estrogen levels shift as well, and that imbalance has its own downstream consequences: increased body fat, loss of muscle, fatigue, mood changes, and higher cardiovascular risk. Treating testosterone without considering the full hormonal picture misses part of the problem.
RegenHRT evaluates estrogen and testosterone together, not as separate issues, but as a single system that needs to be balanced. This is one of the most meaningful differences between what we do and what most providers offer, for both women and men.
The long-term health perspective
The most commonly discussed benefits of hormone therapy are symptom-related: fewer hot flashes, better sleep, improved mood. Of course these matter. But they're not the whole story, and for many of our patients, they're not even the primary reason to pursue treatment.
Hormones are the body's primary regulatory system. When levels drop and stay low, the consequences extend far beyond how you feel.
Maintaining hormone levels within the physiologic range — the range your body actually depended on for decades — is associated with major reductions in long-term health risks. For women, the primary hormones are estrogen, progesterone, and testosterone. For men, testosterone is the foundation, but the research on men's hormone replacement is equally compelling.
- Cardiovascular disease: The risk of heart attack and stroke is 30–50% lower in women on hormone replacement therapy — close to the risk reduction achieved by not smoking — and yet most women have never been told this. Men see similar benefits: a large VA database study found that men treated for low testosterone had a 24% lower risk of heart attack and a 36% lower risk of stroke compared to untreated men with low levels.
- Cognitive health: Women carry roughly double the risk of Alzheimer's disease compared to men, and research suggests much of that disparity is connected to menopause. Hormone replacement reducing that risk substantially, with early research suggesting as much as a 50% drop. Men are not immune: testosterone plays a documented role in cognitive function, and lower levels are associated with increased risk of brain impairment as men age.
- Bone density: Bone loss for women usually starts at menopause - dramatically: up to 5% per year in the first several years . Hormone therapy preserves bone density more effectively than any other treatment, with benefits extending to women at least into their 80s. Men lose bone mass with age as well, driven largely by declining testosterone, and are underdiagnosed for osteoporosis despite real fracture risk.
- Muscle mass: Testosterone plays a critical role in maintaining muscle in both women and men. Without it, muscle wasting occurs even in active, otherwise healthy people, a condition called sarcopenia. Hormone therapy helps preserve the muscle architecture that supports metabolism, strength, and mobility across both sexes. Testosterone replacement, even after many years of low levels, helps both men and women actually rebuild lost muscle, strength, and stamina.
- Metabolic function: Hormone balance maintains healthy metabolism and body composition in ways that diet and exercise alone cannot fully compensate for once levels drop. This holds for women managing weight changes through perimenopause and menopause, and for men experiencing the gradual body composition shifts (more fat, less muscle) that accompany testosterone decline.
- Overall mortality: The VA study referenced above found that men treated for low testosterone had a 51% lower risk of dying from any cause compared to untreated men with low levels. Few interventions in medicine carry that kind of population-level impact.
The RegenHRT approach goes beyond targeting the levels that reduce symptoms and restores hormones to levels associated with disease prevention. The goal is a healthier trajectory, not just a more comfortable present.
| Estradiol level | Physiologic effect |
|---|---|
| <10 pg/mL | Severe deficiency state |
| 10–20 pg/mL | Bone loss accelerated |
| 20–30 pg/mL | Vaginal tissue improves; less bone loss |
| 30–50 pg/mL | Vasomotor symptoms improve |
| 60–100 pg/mL RegenHRT target | Normal bone turnover and markers of blood vessel health |
Based on physiologic literature from UK and Australian hormone research. Individual targets may vary.
Symptoms hormone therapy may address
Hormonal imbalance can affect nearly every system in the body. The symptoms patients experience are often attributed to stress, aging, or lifestyle, when the underlying driver is hormonal deficiency.
Fatigue
Brain fog
Sleep disruption
Weight gain
Hot flashes and night sweats
Low libido
Mood changes and irritability
Joint pain
Memory and concentration problems
Loss of strength and stamina
→ Learn more about hormone therapy for perimenopause
→ Learn more about hormone therapy for menopause
Low energy
Loss of strength and muscle mass
Low motivation
Decreased sex drive
Brain fog
Increased body fat
Mood changes
Who benefits from RegenHRT
RegenHRT is designed for patients who want hormone therapy performed with clinical precision — comprehensive evaluation, individualized dosing, and ongoing monitoring rather than a one-size-fits-all prescription.
Perimenopause can begin in the 30s, long before periods stop. The earliest hormonal shift is usually a drop in testosterone (affecting energy, motivation, and libido), followed by declining progesterone, which creates an estrogen-dominant imbalance experienced as PMS-like symptoms, mood and changes, heavier or more irregular periods, and weight gain.
Most conventional providers don't address perimenopause because they rely on a single diagnostic question: are you still having periods? If yes, they assume hormones are fine. They often aren't.
RegenHRT evaluates hormonal status based on symptoms and labs, not just cycle status.
At menopause, the hormonal shifts of perimenopause reach their endpoint. The ovaries stop producing estrogen and progesterone altogether. This is the stage when long-term health risks — cardiovascular, cognitive, skeletal — start rising, some of them quite suddenly.
The best outcomes from hormone therapy, including the most robust reductions in heart attack, stroke, and dementia risk, are seen in women who begin within the first few years of menopause. Earlier is generally better, but meaningful benefits, particularly for bone density, energy and quality of life extend to women well into their 60s and 70s.
One important note: Because studies on the effects of hormone replacement often focus on specific numerical data (blood pressure, bone density, lean mass…) the results that are most important to patients are often ignored: 90% women report feeling much better in general with hormone replacement.
Read Dr. Lo's full breakdown of the RegenHRT approach to menopause
One of the most common misconceptions we encounter is that menopause is something you get through, and that once you're on the other side, hormones no longer apply to you. Many post-menopausal women have been told explicitly that it's too late, that their window has closed, or that hormone therapy is only appropriate around the time of transition.
For many women, it's this belief that has caused the most harm. And nothing could be further from the truth.
Menopause isn't a phase that ends. Once the ovaries stop producing estrogen and progesterone, they don't start again. A woman who is “post-menopausal” has been living in a state of hormone deficiency for however many years have passed since her last period, and that deficiency has been accumulating consequences the entire time, whether she can feel them or not.
The research is clear that the most robust disease prevention benefits — cardiovascular, cognitive, skeletal — come when hormone therapy begins within the first ten years of menopause. Earlier is better. But benefits continue well beyond that window:
- Bone density responds to hormone therapy at any age. Studies have shown that estrogen replacement increases bone density in women in their 70s and 80s, long after conventional medicine stops offering it.
- Muscle mass and strength continue to benefit from testosterone replacement regardless of how long levels have been low.
- Quality of life improvements are consistently reported by post-menopausal women who begin hormone therapy, even decades after menopause — better energy, sleep, cognitive clarity, and physical comfort — often in areas they had stopped associating with hormones at all.
- Vaginal and urinary healthrespond well to localized hormone therapy at any stage after the onset of menopause, with improvements in comfort, function, and recurrent infection risk.
What we tell post-menopausal women — especially those who were told years ago that hormones weren't for them — is this: you don't know what you've been missing until you address the deficiency. In our experience, about four out of five women who begin hormone therapy years after menopause report feeling better within three months, often in ways they didn't anticipate.
It's not too late. The question worth asking is what's been lost in the time that passed, and what can still be recovered?
Men's testosterone levels typically decline gradually over decades, slowly enough that the changes are often attributed to "just getting older" rather than a hormonal shift with a medical solution. Loss of energy, strength, motivation, sex drive, and muscle are all common presentations.
Testosterone replacement in men has been associated with major reductions in cardiovascular risk and improvements in energy, body composition, and overall wellbeing.
About 30% of our hormone therapy patients are men. About half of them were brought in by a partner or spouse who recognized the change before they did.
Many patients come to RegenCen after unsatisfying experiences with hormone therapy elsewhere. Sometimes their previous provider relied on symptom relief rather than lab monitoring, or used synthetic rather than bioidentical hormones, or didn't include testosterone in the picture at all, or don’t seem to be very diligent or knowledgeable in their approach to hormone replacement.
Patients transitioning from the providers go through the same process as a new patient consultation: comprehensive labs, full medical history review, and a treatment plan built around where you actually are, not where a standard protocol assumes you should be. If you've been on hormone therapy and don't feel the way you expected to, that's worth investigating.
Men on testosterone replacement: quality of life
- Feel better overall
- >90%
- More energy and motivation
- 88%
- Better strength and stamina
- 75%
- Improved sleep
- 66%
- Stronger sex drive and erection function
- 60%
Reduced disease risk
- Lower heart attack risk
- 24%
- Lower stroke risk
- 36%
- Lower all-cause mortality
- 51%
Quality of life data from RegenCen clinical outcomes. Disease risk data from VA database study of men treated for low testosterone vs. untreated men with low levels.
Why physician-guided hormone therapy matters
Hormone therapy has become more accessible, which is largely a good thing. But accessibility without clinical oversight creates real risks. The quality of care varies dramatically depending on who is prescribing, how they're dosing, and whether they're monitoring levels over time.
Two common failure modes exist in hormone therapy today:
- Under-dosing without monitoring. Many conventional providers still follow decades-old guidelines: lowest effective dose, shortest possible duration. The problem is that "effective" has historically been defined as symptom relief instead of physiologic restoration. A dose that quiets hot flashes may still leave a patient's estrogen levels well below the range needed to protect bone, cardiovascular health, and cognitive function. Without regular lab tests, there's no way to know.
- Over-dosing at wellness clinics. At the other end, some hormone clinics operating outside traditional medical oversight push levels far beyond the physiologic range, particularly with testosterone. Super-physiologic dosing in women can cause significant side effects and removes the safety guardrails that come from targeting the range your body was designed to operate in.
The goal of RegenHRT is neither of these. It's precision: levels confirmed by labs, adjusted over time, within the physiologic range your body has always operated in and still recognizes.
Dr. Lo has practiced medicine for more than 35 years and has led RegenCen's bioidentical hormone therapy practice since its founding. He trains all RegenCen providers directly and remains involved in complex and higher-risk cases.
RegenCen providers hold menopause certification across the clinical team, a designation that requires prolonged training, education and rigorous certification testing. That distinguishes providers who specialize in hormone therapy from those who treat it as a sideline.
About two-thirds of our clinical practice is hormone replacement therapy. This is not a service we added. It's what we do.
Explore the research behind RegenHRT
Methodology
Bioidentical hormones explained: what they are, how they work, and why the molecular difference matters
Dr. Lo on the long-term health case for testosterone replacement in men, including cardiovascular risk reduction, lean muscle preservation, metabolic health, and mortality data.Women's Health
Hormone therapy for menopause: the RegenHRT approach
Dr. Lo walks through why conventional hormone therapy often falls short for menopausal women — and how RegenHRT addresses those gaps.Men's Health
Testosterone and longevity: why restoration matters beyond symptom relief
Dr. Lo on the long-term health case for testosterone replacement in men, including cardiovascular risk reduction, lean muscle preservation, metabolic health, and mortality data.Women's Health
Why sleep gets harder after menopause, and what hormone therapy can do about it
How estrogen and progesterone loss disrupts sleep, why sleep medications often miss the underlying cause, and what treatment actually addresses it.Women's Health
Hormone therapy after 60: what's still possible, and why it's worth reconsidering
For women who were told hormones aren't appropriate later in life — a closer look at estrogen's protective effects and how HRT compares to medications commonly prescribed for osteoporosis and depression.Research
Estrogen 101: why women need it, how it's replaced, and what pellet therapy offers
A foundational look at estrogen's role in women's health, the types of estrogen replacement available, and how pellet therapy compares to other delivery methods.
