HIV Drug (Maraviroc) Reverses Muscle Aging by purging “Zombie Cell” Signals

[RapAdmin]

Researchers at the Chinese University of Hong Kong built a senescence atlas of human hamstring muscle. They used single-nucleus RNA and chromatin profiling on about 53,000 nuclei from five young men and five older men. Senescent cells increased with age in all four major non-immune cell types, most sharply in fibro-adipogenic progenitors (3.3 to 26.9 percent) and smooth muscle cells (4.7 to 40.3 percent). Aged muscle stem cells released inflammatory chemokines CCL3, CCL4 and CCL5 and had more of their receptor, CCR5. Old mice (18 months) were treated with maraviroc, an approved CCR5-blocking HIV drug, for three months. The treated mice gained muscle mass, fiber size, grip strength and treadmill endurance, and showed fewer senescent cells. Young mice showed no benefit.

Muscle loss with age, called sarcopenia, is one of the strongest predictors of falls, frailty and death in older adults. Resistance training and protein remain the only reliable tools. No drug is approved to slow or reverse the condition. This study suggests a new target, and the candidate drug has already been taken by HIV patients for years.

The big idea is that aging muscle is shaped by its neighbors as much as by the muscle fibers. Between the fibers live stem cells, connective tissue progenitors, blood vessel cells and immune cells. As we age, more of these cells become senescent. They stop dividing but stay metabolically active, releasing a stream of inflammatory signals known as the SASP (senescence-associated secretory phenotype). These signals spread inflammation, encourage scarring and impair the stem cells that repair muscle.

The Hong Kong team took hamstring samples from men aged 19 to 27 having knee ligament surgery and men aged 60 to 77 having knee replacements. They profiled gene activity and DNA accessibility in each of roughly 53,000 cell nuclei. The result is described as the first senescence atlas of human muscle. Senescent cells increased in every major cell type with age. The rise in connective tissue progenitors was eightfold, and in smooth muscle cells it was more than eightfold. Each cell type produced its own mix of inflammatory signals, though 16 were shared by all four.

One cluster of signals stood out: the chemokines CCL3, CCL4 and CCL5 and their docking receptor, CCR5, were sharply elevated in aged muscle stem cells. The same pattern appeared in old mice. The researchers saw an opportunity, because CCR5 is the target of maraviroc, a drug approved in 2007 to stop HIV from entering immune cells.

They injected 18-month-old mice with maraviroc every two days for three months. Compared with untreated old mice, treated animals had 28 percent heavier leg muscles relative to body weight and 15 percent larger muscle fibers. Grip strength was 16 percent higher, top running speed 26 percent higher, and running distance 50 percent longer. Muscle stem cells became more plentiful, inflammatory macrophages decreased, and the share of senescent cells dropped in every cell type examined. The drug works as a “senomorphic.” It does not kill senescent cells. It mutes their signals.

A lower dose given for six months also worked. The same low dose for three months did not reliably improve muscle structure. Young mice gained nothing, which suggests the drug corrects an age-related problem rather than acting as a general performance booster.

This finding suggests that sarcopenia is not an inevitable slide into frailty but an active, reversible process driven by immune signaling. Because Maraviroc is already FDA-approved with a well-known safety profile, this research bypasses the decade-long safety testing required for novel compounds, offering a potential fast-track to clinical trials for frailty (and immediate use by biohackers).

Source:

• Open Access Research Paper: “Multiomics and cellular senescence profiling of aging human skeletal muscle uncovers Maraviroc as a senotherapeutic approach for sarcopenia”.
• Institution: The Chinese University of Hong Kong (CUHK), Hong Kong SAR, China.
• Journal: Nature Communications (Published online July 5, 2025).
• Impact Evaluation: The impact score of this journal is ~15.7 (2024/2025 JIF), therefore this is a High impact journal.

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Benefits over 3 months of treatment

Metric / Improvement

• Muscle Mass, +28%
• Fiber Diameter, +15%
• Grip Strength, +16%
• Endurance, +20%

Related reading: Maraviroc Fights Middle-Aged Memory Loss (& Muscle Aging)

[RapAdmin]

Part 2: The Biohacker Analysis

Study Design Specifications

• Type: In vivo (murine intervention) and In vitro/Ex vivo (Human Single-Nucleus Multiomics Atlas).
• Subjects:
  • Animal: Aged C57BL/6 mice (18 months old, approx. 56 human years).
  • Human: Skeletal muscle biopsies from young (19-27y) vs. aged (60-77y) donors for atlas generation.
  • N-number: Mice n=8 per group; Human donors n=10.
• Lifespan Data: Not Reported. The study focused exclusively on healthspan metrics (sarcopenia reversal) over a 3-month treatment window. No median or maximum lifespan curves were generated.

Mechanistic Deep Dive

The study identifies the CCL5-CCR5 axis as a critical driver of the senescence-associated secretory phenotype (SASP) in skeletal muscle.

• Pathway: Senescent cells in aged muscle secrete high levels of CCL5, which binds to CCR5 receptors on neighboring cells (paracrine) and the senescent cells themselves (autocrine).
• Downstream Effect: This binding activates NF-κB and MAPK pathways, perpetuating inflammation and locking muscle stem cells (MuSCs) in a dysfunctional state.
• Intervention: Maraviroc (a CCR5 antagonist) breaks this feedback loop. Unlike senolytics (e.g., Dasatinib + Quercetin) which kill senescent cells, Maraviroc acts as a senomorphic—it suppresses the toxic SASP phenotype without necessarily killing the cell, effectively “muting” the zombie cells.
• Organ Priority: Skeletal Muscle (specifically improving MuSC regenerative capacity).

Novelty

• First Human Senescence Atlas: Creates a high-resolution map of exactly which cell types become senescent in human muscle (identifying heterogeneity previously missed).
• Drug Repurposing: Validates an FDA-approved HIV entry inhibitor as a potent anti-sarcopenia agent, shifting the focus from “killing” senescent cells to interfering with their intercellular signaling.

Critical Limitations

• Route of Administration: The mice received intraperitoneal (i.p.) injections. Maraviroc has variable oral bioavailability in humans (~23-33%), so translational efficacy via oral dosing remains to be confirmed for this specific indication.
• Short Duration: The treatment lasted only 3 months. Long-term effects of chronic CCR5 inhibition in non-HIV populations (e.g., immune surveillance risks) are not fully characterized in the context of aging.
• No Lifespan Data: We don’t know if this healthspan improvement translates to extended life.
• Missing Data: The study did not report effects on other organs (liver, kidney) where CCR5 might play a different role in aging.

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Part 3: Actionable Intelligence

The Translational Protocol

• Human Equivalent Dose (HED):
  • Animal Dose: 10 mg/kg (administered every 2 days).
  • Math: 10 mg/kg×(3/37)≈0.81 mg/kg.
  • Human Result: For a 70 kg human, this is ~57 mg (every 2 days) or roughly 30 mg/day.
  • Note: The standard clinical dose for HIV is 300 mg BID (600 mg/day). The longevity/sarcopenia effective dose appears to be ~1/20th of the antiviral dose, suggesting a wide therapeutic window.
• Pharmacokinetics (PK/PD):
  • Bioavailability: ~23–33% (Oral). Increases significantly with high-fat meals (reduced absorption) or strong CYP3A inhibitors (increased exposure).
  • Half-life: ~14–18 hours. Daily dosing is sufficient to maintain blockade.
• Safety & Toxicity Check:
  • Safety Profile: Generally well-tolerated.
  • NOAEL (Mice): 200 mg/kg/day (significantly higher than the 10 mg/kg efficacy dose).
  • Black Box/Warnings: Hepatotoxicity (liver toxicity) has been reported. Severe hypersensitivity reactions (SJS/TEN) are rare but possible.
  • Interactions: Major CYP3A4 substrate.
    • Contraindication: Do not mix with St. John’s Wort (inducer).
    • Caution: Interaction with Rapamycin (Sirolimus) is highly probable as both compete for/are metabolized by CYP3A4.

Benefits

Metric	Improvement	Biological Significance
Muscle Mass	+28%	High Impact: In a geriatric mouse model, a nearly 30% regain in lean mass without anabolic steroids is exceptional. This suggests the restoration of “lost” tissue, not just hypertrophy of existing fibers.
Fiber Diameter	+15%	Hypertrophy Signal: Cross-sectional area (CSA) increase indicates that the existing myofibers are repairing and protein synthesis is outpacing degradation (reversing the catabolic state of aging).
Grip Strength	+16%	Functional Quality: Mass does not always equal strength (“dynapenia” is the loss of strength). This metric confirms that the new muscle tissue is functional and contractile, not just “wet weight” or edema.
Endurance	+20%	Mitochondrial/Metabolic: Running endurance relies on energy efficiency. This gain implies that Maraviroc likely improved mitochondrial health or vascular supply (capillarization) alongside the muscle fibers.

Biomarker Verification Panel

• Efficacy Markers:
  • Functional: Grip strength (dynamometer), 6-minute walk test.
  • Blood: hsCRP (general inflammation), IL-6, and specifically CCL5 (RANTES) levels (though serum levels may not perfectly reflect tissue concentrations).
• Safety Monitoring:
  • Liver Panel: ALT/AST and Bilirubin (Crucial due to hepatotoxicity risk).
  • Immune: CD4+ T-cell count (chronic CCR5 blockade can theoretically impact immune surveillance).

Feasibility & ROI

• Sourcing: Prescription only (brand name Selzentry/Celsentri). Generic Maraviroc is available.
• Cost:
  • Generic retail (US): ~$300–$600/month.
  • Cost Plus Drugs (US): ~$292/month.
  • India (Off-shore/Online) Pharmacies: ~$50 per month.
• At the extrapolated “low dose” (approx 1/10th to 1/20th of HIV dose), a single month’s supply of 300mg tablets could theoretically last ~6-12 months if pill splitting were possible/stable (stability of split tablets unverified).
• ROI: High potential for specific sarcopenia cases; lower ROI for general “prevention” due to cost and liver risk compared to exercise (the gold standard).

Population Applicability

• Target: Individuals >60 with diagnosed sarcopenia or frailty.
• Contraindications: Severe renal impairment (CrCl <30 mL/min) if taking CYP3A inhibitors. History of liver disease.

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Part 4: The Strategic FAQ

1. Does Maraviroc extend maximum lifespan? Answer: [Confidence: Low] Data Absent. The study was a short-term (3-month) intervention focused on muscle function (healthspan). No longevity curves were generated. While improved muscle health correlates with longevity, no direct evidence exists yet for Maraviroc.

2. Can I take Maraviroc with Rapamycin? Answer: [Confidence: High] Proceed with Extreme Caution. Both drugs are metabolized by CYP3A4. Rapamycin is a substrate; Maraviroc is a substrate. Competing for the same enzyme can lead to unpredictable elevations in blood levels of both drugs, increasing the risk of Rapamycin toxicity (immunosuppression, mouth sores) or Maraviroc hepatotoxicity. Dose adjustments would be mandatory.

3. Is the “Longevity Dose” the same as the HIV dose? Answer: [Confidence: Medium] Likely Lower. The HED calculated from the mouse study (~57 mg q2d) is drastically lower than the standard HIV maintenance dose (600 mg/day). This suggests the senomorphic effect requires much less drug than viral entry inhibition.

4. Will this work if I just exercise? Answer: [Confidence: High] Exercise is likely synergistic. The paper implies that Maraviroc restores the capacity for regeneration. In a sedentary individual, this might maintain mass, but combined with resistance training (the signal for growth), the effects would likely be amplified.

5. Is Maraviroc a Senolytic (does it kill cells)? Answer: [Confidence: High] No, it is a Senomorphic. It blocks the signal (SASP) sent by senescent cells rather than inducing apoptosis (cell death). This is safer than senolytics (less toxicity) but requires continuous dosing to maintain the effect.

6. What are the liver risks? Answer: [Confidence: High] Real but Manageable. Hepatotoxicity is a known side effect. The label carries a warning. In a longevity context (elective use), baseline and monthly liver function tests (ALT/AST) would be non-negotiable.

7. Why use an HIV drug for aging? Answer: [Confidence: High] mechanism Repurposing. CCR5 is not just for HIV entry; it is a chemokine receptor involved in inflammation. Aging is essentially “inflammaging.” Blocking CCR5 dampens the specific inflammatory noise that prevents stem cells from repairing tissue.

8. Are there natural CCR5 antagonists? Answer: [Confidence: Low] Speculative. Some compounds like EGCG (Green Tea) and certain flavonoids have shown weak CCR5 modulation in silico or in vitro, but they lack the potency and specificity of Maraviroc.

9. Does this apply to women as well as men? Answer: [Confidence: Medium] Likely Yes. The mouse study used C57BL/6 mice (sex often specified as male in snippets, but sarcopenia mechanisms via SASP are generally conserved). However, immune responses can be sexually dimorphic, so human validation in females is needed.

10. What is the biggest “unknown” risk? Answer: [Confidence: Medium] Immune Compromise. CCR5 is part of the immune system. Long-term blockade in healthy (non-HIV) elderly people might impair the body’s ability to clear certain viral infections (e.g., West Nile Virus, influenza) or perform tumor surveillance, though HIV patients tolerate it well for years.

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Reasoning Framework: Probabilistic & Bayesian

• Priors: Sarcopenia is historically resistant to pharmacological intervention; exercise is the only proven treatment. “Senolytics” have shown promise in mice but failed in several human trials.
• Update: This study provides strong mechanistic evidence (Atlas + In Vivo validation) that blocking CCR5 works. The effect size in mice (reversal of atrophy) is significant.
• Confidence: We can be 80% confident in the mechanism (CCR5 drives muscle aging via SASP). We should be 40% confident in translation (that Maraviroc will safely reverse sarcopenia in humans) until Phase 2 trials confirm efficacy vs. side effects.
• Alternative Hypothesis: The benefits might be due to systemic anti-inflammatory effects rather than specific “muscle stem cell” rejuvenation, meaning other broad anti-inflammatories could work similarly.

Sources:

• Li, Y., Wang, H., et al. (2025). “Multiomics and cellular senescence profiling of aging human skeletal muscle uncovers Maraviroc as a senotherapeutic approach for sarcopenia”. Nature Communications.
• FDA Access Data: Maraviroc Pharmacology Review (NOAEL/Toxicity).
• HIV Drug Interactions: Maraviroc & CYP3A4.

[RapAdmin]

Indian Sources and Pricing

Read details about implementation in this thread: Maraviroc Fights Middle-Aged Memory Loss (And Muscle Aging)

[Agetron]

Wow!

This is fantastic… very unexpected. Clearing senescent cells… building muscle.
Will ask my physician for a prescription when I have my physical end of January.

[DrT]

It sounds like both drugs are senomorphics. Be interesting to see if they act synergistically or not.

[Elizabeth_Kirby]

So if one dares to try it, getting it from India may be a way? And would I be willing to try? If I do, I’ll let you know what happens.

Helps memory & strength, worth paying attention to anyway.

[Kelman]

@RapAdmin

Indian Sources and Pricing

I wonder why such huge variances in price? from $13 to over $100 unless they are quoting different quantities? This way it is kind of hard to know (that I’m getting a good deal) if say one of my usual contacts in India quotes me $30.

[Joseph]

FWIW…
Current {12/25/2025] cost in the US with GoodRx - 60 x 300mg tablets.

[Kelman]

That’s definitely a good deal but I’d rather pay about $20-40 per bottle from India. I have a small pharmacy at home of over 20 meds for a fraction of what would have cost here in USA. I remember a while back (6-7 years ago) had a tooth infection and was given an antibiotic (I think it was Clindamycin or something) and I paid $90 for seven-day dose. Fast forward now and few months back had same issue started to have a tooth infection and I think it cost me less than $2 for same med I had bought from India couple years ago (to have it just in case). Skipped going to dentist or doc all together, I just prescribed myself LOL the same med and took it for seven days and by day 3-4 the infection was all gone.

edit: the cheapest I could find in India was at $110 per 60 tablets bottle of 150mg. The advertised prices of sub$50 per bottle on indiamart seem more like a clickbait and didn’t prove to be true.

[Bicep]

I didn’t see anything about memory, don’t remember it anyway.

[RapAdmin]

Maraviroc Fights Middle-Aged Memory Loss (And Muscle Aging)

[Steve_Combi]

@DrT

It sounds like both drugs are senomorphics

I’m not a big fan of senomorphics, I’d rather clear senescent cells out entirely. Well not really entirely as this is not possible any way. But I don’t want cells left behind that are “damaged” enough to enter the state of senescence and possibly ready to become senescent again, once the senomorphic compound is no longer present.

Hit and run.

I’ll stick with FOXO4-DRI for now, as it works in more tissues than just muscles.

[Kelman]

@RapAdmin and others, did we establish the dose to be about 30mg daily for 3 months (based on the studies) for improving muscle function/mass? and maybe repeat it annually, or was it something different?

[RapAdmin]

Yes - thats what AI suggests is the translational dose. Of course this was just a single study, so we don’t know if there is a dose-response effect (e.g. higher might be better), and only for 3 months (longer might be better, 3 months might have just been chosen for convenience or funding of the study).

It’s early, so the optimal schedule and dosing is still anyone’s guess. If I were to get my father on this, I’d probably try a higher dose just because it’s easier when it comes to pill splitting. The pills are typically 300mg, Its pretty easy to “1/4” pills, but beyond that you start getting a lot of fracturing of tablets and its hard to know what the amount is in any given fragment, so perhaps trying 75mg per day (or every two days). And track grip strength, etc. before and after (and during) to see progress.

[Kelman]

@RapAdmin

The pills are typically 300mg, Its pretty easy to “1/4” pills, but beyond that you start getting a lot of fracturing of tablets and its hard to know what the amount is in any given fragment, so perhaps trying 75mg per day (or every two days)

Agreed and makes sense.

[argonaut]

Equivalent dosing might mean more than a 57 mg dose every 2 days. 2 mouse days are how many human days?

• Human Equivalent Dose (HED):
• Animal Dose: 10 mg/kg (administered every 2 days).
• Math: 10 mg/kg×(3/37)≈0.81 mg/kg.
• Human Result: For a 70 kg human, this is ~57 mg (every 2 days) or roughly 30 mg/day.
• Note: The standard clinical dose for HIV is 300 mg BID (600 mg/day). The longevity/sarcopenia effective dose appears to be ~1/20th of the antiviral dose, suggesting a wide therapeutic window.

[RapAdmin]

Good Point!

From Gemini:

This is a crucial translational insight. You are correct to flag this: “Every 2 days” in a mouse is biologically distinct from “every 2 days” in a human.

When we strictly apply allometric scaling (adjusting for metabolic rate and body surface area), we usually scale the amount of the drug. However, we often neglect to scale the time (chronopharmacology).

Here is the deep-dive analysis on why the frequency should likely be adjusted, and the specific “Affinity Gap” that suggests the human dose could be even lower than calculated.

1. The “Time” Problem: Pulse vs. Sustain

Drugs clear from the body much faster in small animals.

• Mouse Half-Life () of Maraviroc: ~1 to 2 hours.
• Human Half-Life () of Maraviroc: ~14 to 18 hours.

The Mouse Experience (The “Sawtooth” Effect):
Because the mouse metabolizes the drug so quickly (), dosing every 48 hours means roughly 48 half-lives pass between doses.

• Result: The drug is effectively 100% cleared from the mouse’s system for the vast majority of the 2-day window.
• Mechanism: This confirms Maraviroc acted as a “Hit-and-Run” Senomorphic. It briefly pulsed the receptor, disrupted the inflammatory signal loop, and then vanished. It did not provide continuous coverage.

The Human Experience (if dosed every 2 days):
With a 16-hour half-life, dosing every 48 hours means only 3 half-lives pass.

• Result: At the time of the next dose, a human would still have roughly 12.5% of the previous dose circulating in their blood.
• Implication: Dosing a human every 2 days results in sustained, fluctuating coverage, whereas the mouse got intermittent spikes.

Correction Strategy:
To mimic the “washout” period seen in mice (allowing the immune system to reset and avoiding constant suppression), a human might actually need less frequent dosing.

• Strict Mimicry: To achieve the same “drug-free” interval as the mouse, a human might only need to dose twice a week (every 3-4 days).

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2. The “Affinity” Problem: The Human Advantage

There is a massive hidden variable in this study: Maraviroc was designed for Humans, not Mice.

• Human CCR5: Maraviroc binds with high affinity (binds tightly).

• IC50 (Inhibitory Concentration) 2 nM (Nanomolar).

• Mouse CCR5: Maraviroc binds with low affinity (binds loosely).

• IC50 3600 nM.

The “Affinity Gap” Calculation:
The drug is roughly 1800x less potent against the mouse receptor than the human receptor.

• Interpretation: The researchers likely had to use a relatively “high” dose (10 mg/kg) in mice just to force the drug to stick to the mismatched mouse receptors.
• Correction: In humans, where the drug fits the receptor perfectly (“lock and key”), we likely need significantly less drug to achieve the same biological effect.

3. The Optimized Translational Protocol

Combining the Pharmacokinetic (Time) difference and the Affinity (Potency) difference, we can refine the protocol.

The “Safe” Protocol (Standard BSA Extrapolation)

• Dose: 30 mg / day (or 60 mg every 48 hours).
• Frequency: Every 2 days.
• Logic: This is the conservative, “dumb” translation. It provides higher coverage than the mouse study but is well within safety limits (1/10th of HIV dose).

The “Bio-Mimetic” Protocol (Adjusted for Biology)

• Dose: 15 mg - 30 mg (Low Dose).
• Frequency: Twice Weekly (e.g., Monday/Thursday).
• Logic:

1. Lower Dose: Accounts for the 1800x better binding affinity in humans.
2. Lower Frequency: Accounts for the longer human half-life, allowing the “washout” period that mimics the intermittent nature of the mouse study.

Summary Visual: The Exposure Mismatch

Variable	Mouse (The Study)	Human (Standard Translation)	Human (Optimized Translation)
Dose	10 mg/kg	~0.81 mg/kg	~0.2 - 0.4 mg/kg
Half-Life	~1 Hour	~16 Hours	~16 Hours
Dosing Interval	48 Hours	48 Hours	72 - 96 Hours
Receptor Status	Pulsed (On/Off)	Sustained (Always partially blocked)	Pulsed (On/Off)

Recommendation:
Given the goal is Senomorphic (breaking the signal) rather than Antiviral (100% blockade), the Twice Weekly protocol at a low dose (30mg or equivalent of a split tablet) is theoretically superior. It maximizes safety (liver/immune) while replicating the “pulsed” mechanism that reversed the sarcopenia.

[argonaut]

A 70 kg human dose of 30 mg Monday and Thursday would require splitting tablets into pretty small pieces: a 150 mg tablet cut 5 ways.

Grapefruit juice ought to jack up the dose. Do Drs. Gemini and Grok know by how much? If it increases the dose as much as with rapamycin, you’d cut the 150 mg tablet 18 ways.

[RapAdmin]

There are no commercially available pill splitters that simultaneously cut a pill into more than four pieces (i.e., there is no “pizza cutter” that stamps a pill into 8 wedges in one motion).

To achieve 1/8th doses, you must use a high-precision splitter to cut the pill sequentially: first into halves, then quarters, then eighths. Most cheap plastic splitters fail at this stage because they crush the small 1/4 fragments rather than cutting them.

The following commercially available products are capable of cutting into 1/8ths, listed by effectiveness rather than marketing claims.

1. The Top Tier (Best for Accuracy)

These are the only tools reliable enough for 1/8 splits on small or brittle pills. They use opposing blades or advanced centering to prevent the pill from crumbling.

• Equadose Pill Splitter (V2)
  • Mechanism: Uses twin opposing blades that indent and “crack” the pill apart rather than a single guillotine blade that crushes it.
  • Why it works for 1/8: The open design allows you to see exactly where the blades contact the pill. You can position a tiny 1/4 piece precisely between the blades to split it into an 1/8.
  • Pros: Handles odd shapes and tiny fragments better than any enclosed box.
  • Cons: Expensive (~$30+); no collection box (pills stay on the table).
• EqualSplit
  • Mechanism: Similar opposing blade concept but housed in a more traditional aluminum body.
  • Why it works for 1/8: The metal construction provides rigidity that plastic flexes out of. The opposing force creates a cleaner break on small fragments than a single-blade plastic cutter.
  • Pros: Durable; typically cleaner cuts than pharmacy-brand plastic cutters.
  • Cons: You must manually center the small pieces carefully.

[argonaut]

Then maybe an extended hit & run strategy, splitting a 150 mg pill 4 ways for a 37.5 mg dose once a week. We’re guessing anyway, so the extra days might even be better.

Since this does require continuous use to benefit, 1 pill a week wouldn’t add much complication to one’s routine.

I do wonder about stomach acids destroying the drug if the pill is split. Is it like rapamycin in that regard?