Why low dose naltrexone (LDN)Why the best hormone clinics use both
Restoring testosterone, estrogen, or progesterone to optimal levels can reverse years of accumulated fatigue, cognitive decline, and metabolic dysfunction. The clinical evidence is clear and the patient experience is often transformative.
But not always completely transformative. A significant number of patients who begin HRT report meaningful improvement in some areas while continuing to struggle in others. The libido returns but the energy does not. The mood stabilizes but the mental clarity remains inconsistent. The body composition shifts but recovery from exercise stays sluggish.
These partial responses are frustrating, and they are far more common than the marketing around hormone therapy would suggest.
And the clinics producing the most consistent, comprehensive outcomes for their patients are the ones that have recognized what a growing body of research now supports: hormone replacement therapy and NAD+ work through complementary biological pathways, and combining them produces results that neither achieves alone.
Two systems, one problem
Hormones travel through the bloodstream and bind to receptors on target cells, instructing those cells to carry out specific functions. Testosterone tells muscle cells to synthesize protein. Estrogen tells neurons to maintain synaptic plasticity. Progesterone tells the nervous system to modulate GABA activity. When hormone levels decline, these signals weaken, and the downstream effects are felt as the familiar symptoms of aging: fatigue, weight gain, brain fog, mood instability, loss of drive.
NAD+ operates on a different level entirely. Nicotinamide adenine dinucleotide is a coenzyme required for hundreds of metabolic reactions inside every cell, including the production of ATP through oxidative phosphorylation, the activation of sirtuins that regulate gene expression and DNA repair, and the clearance of reactive oxygen species that damage cellular structures over time. NAD+ gives cells the energy and enzymatic support they need to actually do it.
The biology that connects them
Peer-reviewed research has established direct mechanistic links between sex hormone status and NAD+-dependent cellular processes. A 2018 review published in Frontiers in Neuroscience documented that estrogen promotes mitochondrial electron transport chain activity, stabilizes mitochondrial membrane potential, and reduces reactive oxygen species production in brain tissue (Grimm et al., Frontiers in Neuroscience, 2018).
Estrogen and testosterone decline directly impair the mitochondrial systems that NAD+ fuels. A 2024 review in Antioxidants confirmed that estrogen and SIRT3 work together to protect mitochondria; without estrogen, sirtuins lack activation, and without NAD+, they lack fuel. Similarly, low testosterone impairs mitochondrial biogenesis and SIRT1 activity.
These declines are biochemically entangled rather than independent events. Because hormones support the enzymes that NAD+ activates, losing one accelerates the loss of the other. Restoring both creates a reinforcing cycle of recovery that neither treatment can achieve alone.
| Biological function | What HRT addresses | What NAD+ addresses |
|---|---|---|
| Cellular energy (ATP production) | Indirect: hormones support mitochondrial gene expression | Direct: NAD+ is a required substrate in oxidative phosphorylation |
| DNA repair | Indirect: estrogen and testosterone reduce oxidative DNA damage | Direct: NAD+ fuels PARP enzymes that repair broken DNA strands |
| Inflammatory regulation | Direct: estrogen suppresses NF-kB; testosterone modulates cytokine production | Direct: NAD+ activates SIRT1, which downregulates NF-kB signaling |
| Mitochondrial biogenesis | Direct: testosterone promotes PGC-1α expression | Direct: NAD+ activates SIRT1/PGC-1α axis to generate new mitochondria |
| Cognitive function | Direct: estrogen maintains synaptic plasticity; testosterone supports executive function | Supportive: NAD+ provides the metabolic energy neurons need to respond to hormonal signals |
| Sleep and circadian rhythm | Direct: progesterone modulates GABA; estrogen influences melatonin | Direct: NAD+ follows circadian oscillation via NAMPT enzyme regulation |
What partial recovery actually looks like
Libido improved, but sustained physical energy did not. Mood stabilized, but the afternoon cognitive fade persists. Sleep quality got better, but recovery from workouts or illness remains slower than expected. Weight started shifting, but the stubborn visceral fat around the midsection has not budged. These are not signs that hormone therapy has failed. They are signs that the cellular energy infrastructure has not been addressed.
- In women, estrogen decline during perimenopause directly impairs mitochondrial function in the brain and in metabolically active tissues. Replacing estrogen restores the hormonal signal, but if NAD+ levels remain depleted, the mitochondria receiving that signal still lack the coenzyme they need to translate it into energy. This is why some women on HRT report that their hot flashes resolved but their brain fog lingered, or that their sleep improved but their daytime stamina did not match.
- In men, testosterone replacement often restores drive, strength, and confidence within weeks. But testosterone also increases metabolic demand on cells. When NAD+ is insufficient, the increased demand can create a bottleneck in which cells are being asked to do more without the substrate to do it efficiently. This can manifest as elevated inflammation, slower recovery, and persistent fatigue that does not align with otherwise favorable hormone levels.
The compounding decline
A large-scale study published in Frontiers in Endocrinology analyzing whole blood NAD+ levels in over 1,500 participants found a significant decline in NAD+ concentrations in men before age 50, with the most pronounced drop occurring in the 40 to 49 age range. This is the same decade during which testosterone levels in men decline meaningfully and estrogen levels in women begin their perimenopausal descent. The timing is not coincidental. It reflects a period of converging biological losses that, when left unaddressed, accelerate each other.
This is the compounding problem. Lower hormones reduce sirtuin expression. Reduced sirtuin activity impairs mitochondrial repair. Impaired mitochondria produce less NAD+. Less NAD+ further reduces sirtuin function. The cycle feeds itself, and each year the gap between how you feel and how you want to feel widens slightly.
Breaking this cycle requires intervention at both levels. HRT restores the hormonal signals that support mitochondrial gene expression and sirtuin activity. NAD+ restores the coenzyme that sirtuins and mitochondria need to act on those signals. Together, they interrupt the downward spiral and replace it with a reinforcing upward one.
| Why the order mattersIn clinical practice, most patients begin with comprehensive bloodwork and hormone optimization before adding NAD+ therapy. This sequence allows the clinical team to establish a hormonal baseline, identify metabolic and nutritional contributors, and then introduce NAD+ into an environment where the hormonal signals are already being restored. The result is a faster, more durable response to NAD+ infusions because the cells receiving the coenzyme are also receiving the hormonal support they need to use it effectively. |
How Katalyst Wellness combines them
At Katalyst Wellness, NAD+ can be added to your hormone replacement therapy protocol. It is prescribed as part of a physician-guided protocol that begins with comprehensive bloodwork testing in San Diego covering over 60 biomarkers across hormonal, metabolic, thyroid, inflammatory, and nutritional categories. This diagnostic foundation determines not only whether HRT is appropriate but also whether NAD+ therapy will meaningfully accelerate results.
For patients already on a hormone protocol who are experiencing partial improvement, adding NAD+ IV therapy in San Diego often addresses the residual symptoms that hormones alone could not reach. For new patients, the combination can be introduced from the outset when bloodwork and clinical history suggest that both hormonal decline and cellular energy depletion are contributing to the symptom picture.
Dr. Camhi and the clinical team evaluate each patient individually. There is no protocol that fits everyone, and the decision to combine NAD+ with HRT depends on the specific biomarker patterns, symptom severity, and health goals of the person sitting in the chair. What does not change is the clinical philosophy: treat the complete biology, not a single lab value.
What patients typically report
The subjective experience of combining NAD+ and HRT tends to follow a recognizable trajectory. Patients who were already on hormone therapy and felt partially better describe a second wave of improvement after beginning NAD+ infusions. The descriptions are consistent across gender and age.
Energy becomes more sustained rather than front-loaded in the morning. Mental clarity sharpens in a way that feels qualitatively different from stimulant-driven alertness. Physical recovery accelerates noticeably. Sleep deepens. Mood becomes more resilient under stress rather than reactive. And the overall sense of vitality shifts from adequate to genuinely strong. Several patients have described the experience as finally feeling like the hormones are actually working, which is an accurate intuition. The hormones were always working. The cells just did not have the metabolic resources to fully respond until NAD+ was introduced.
The safety profile of combining both therapies
NAD+ and HRT operate through entirely different biological mechanisms. NAD+ is a coenzyme involved in metabolic reactions. Hormones are signaling molecules that bind to nuclear and membrane receptors. There are no known pharmacological interactions between intravenous NAD+ and bioidentical hormones, and clinical practitioners who prescribe both report that the combination is well tolerated when administered under appropriate medical supervision.
That said, combining any two therapies requires monitoring. At Katalyst Wellness, patients on a dual NAD+ and HRT protocol receive regular follow-up bloodwork to track hormone levels, hematocrit, metabolic markers, and inflammatory indicators. This is the same standard of care applied to all patients on hormone therapy for women and testosterone replacement therapy for men in San Diego, with the addition of clinical attention to how NAD+ infusions are influencing energy, cognition, and recovery between sessions.
Who should consider combining NAD+ and HRT
You started hormone therapy and improved noticeably, but you have not reached the level of energy, clarity, or resilience you expected. You are over 40 and experiencing a convergence of symptoms that span hormonal, cognitive, and metabolic categories.
You have tried optimizing sleep, nutrition, and exercise and still feel as though something fundamental is missing. You are recovering from a period of intense stress, illness, or burnout and your body has not bounced back the way it used to.
Or you are pursuing a comprehensive wellness strategy that includes both hormonal optimization and metabolic support, possibly alongside a structured approach to body composition through our medical weight loss program in San Diego, and you want every intervention to reinforce every other one rather than operating in isolation.
In each of these scenarios, the issue may not be that your treatment is wrong. It may be that your treatment is incomplete. A single conversation with the team at Katalyst Wellness, supported by thorough diagnostic bloodwork, can clarify whether adding NAD+ to your protocol is the step that closes the gap.
| The complete approach: If you are already on HRT and want more from it, or if you are exploring hormone therapy for the first time and want to start with the most complete strategy available, Katalyst Wellness in San Diego can build a protocol that addresses both your hormonal health and your cellular energy. Book a consultation and find out what combining NAD+ and HRT can do for you.→ Schedule your consultation |
Frequently asked questions
Can I start NAD+ and HRT at the same time?
Yes. In many cases, both therapies can be initiated concurrently. However, most clinicians prefer to begin with bloodwork and hormone optimization first so that baseline hormonal data is clear before NAD+ is introduced. Your provider will recommend the best sequencing based on your individual results.
How quickly will I notice a difference from adding NAD+?
Many patients report improvements in energy and mental clarity within the first one to two infusions. The most sustained and comprehensive results typically emerge after a loading series of several sessions. Individual responses vary depending on the severity of NAD+ depletion and the presence of other contributing factors.
Is there anyone who should not combine these therapies?
Both NAD+ IV therapy and bioidentical HRT have favorable safety profiles when prescribed and monitored by qualified physicians. Patients with specific contraindications to either therapy will be identified during the initial evaluation. Your provider will review your full medical history before recommending a combined protocol.
Do I need NAD+ infusions indefinitely?
Not necessarily. Many patients benefit from an initial loading phase followed by periodic maintenance infusions. The frequency and duration depend on your response, your lifestyle, and the results of ongoing bloodwork. Some patients transition to oral NAD+ precursors for long-term maintenance after their IV series is complete.
Will my insurance cover NAD+ therapy?
NAD+ IV therapy is generally not covered by insurance. Katalyst Wellness offers transparent pricing for all treatments, and our team can help you understand the cost structure before beginning a protocol.
