A drug pairing often promoted in anti-aging research may come with an unexpected cost in the brain. University of Connecticut scientists report in PNAS that dasatinib+quercetin (D+Q) caused significant brain damage in mice, including the loss of myelin, the fatty covering that helps nerve cells send signals quickly and efficiently.
https://scitechdaily.com/popular-anti-aging-treatment-may-actually-cause-brain-damage/
That is not good news. Many forum members are trying or have tried the D+Q senolytic treatment.
https://www.pnas.org/doi/abs/10.1073/pnas.2524897123
Sadly behind a paywall, but chatGPT:
Here is a careful read of it based on the indexed PNAS abstract/full-text snippets, the journal metadata, and the University of Connecticut press release. I could not directly open the full PNAS page in the browser tool because PNAS returned a 403, so I am being cautious about anything that goes beyond what those sources clearly support. (PNAS)
Paper
Senolytic treatment induces oligodendrocyte dysfunction and demyelination in the corpus callosum, published in PNAS on March 16, 2026. The study examines the senolytic combination dasatinib + quercetin (D+Q), a regimen widely discussed in aging research and already being tested clinically in several human settings, including Alzheimer’s-related trials and at least one MS-related study listing. (EurekAlert!)
The main claim is that D+Q, instead of helping brain white matter, caused oligodendrocyte dysfunction and demyelination in the mouse corpus callosum. The key implication is that a senolytic cocktail often framed as broadly “anti-aging” may have a harmful effect on CNS myelin, at least in this mouse context. (PNAS)
According to the abstract snippets and press coverage based on the paper, treated mice had substantial loss of myelin in the corpus callosum, and the corpus callosum itself became markedly reduced. The effect was reported in both young and old mice, with the damage described as worse in younger mice. (Medical Xpress)
Mechanistically, the authors appear to argue that the oligodendrocytes did not simply die off. Instead, they entered a dysfunctional state: the cells regressed toward a more immature or juvenile-like phenotype, their metabolism became abnormal, and transcriptional programs shifted away from myelination while upregulating unfolded protein response / stress pathways. (Medical Xpress)
The press release frames this as potentially relevant in two directions. First, it is a safety warning for enthusiastic off-label or prophylactic use of D+Q in aging. Second, because the cells appear to regress rather than die, the work may offer clues about reversible myelin failure and disorders such as multiple sclerosis. (EurekAlert!)
The biggest novelty is not that senolytics can have side effects; it is that a flagship senolytic combination appears to produce a specific white-matter toxicity phenotype in the brain, centered on oligodendrocytes and myelin, rather than a generic toxicity readout. That is a much sharper and more biologically informative finding than “the treatment was harmful.” (PNAS)
A second novel point is the suggestion that D+Q causes oligodendrocytes to dedifferentiate or revert to a less mature state rather than undergo outright cell loss. That is conceptually important because it implies a drug-induced shift in cell state and function, not merely ablation. (Medical Xpress)
A third novel aspect is the age pattern: the reported injury was more severe in younger mice, which cuts against the simple expectation that older tissue would always be more vulnerable. That hints that the affected pathway may be tied to the metabolic demands of active myelin maintenance rather than just frailty or aging burden. This is still an inference, but it is consistent with how the results were described. (Medical Xpress)
A fourth novelty is translational context. D+Q is not just a theoretical lab tool; it is already in or around human clinical testing for age-related indications, including brain-related ones. That makes this paper more consequential than a purely exploratory animal toxicology result. (ClinicalTrials)
The study appears strong in that it links structure, cell state, and transcriptional change: demyelination in white matter, oligodendrocyte dysfunction rather than simple death, and a transcriptomic shift away from myelination with stress-response activation. When histology and cell-state transcriptomics point in the same direction, that usually makes the biological signal more persuasive. (Medical Xpress)
It is also a strength that the effect was reported across young and old mice, because that reduces the chance that the finding is just an idiosyncrasy of extreme aging. (EurekAlert!)
The biggest limitation is species and context. This is a mouse-brain result. It does not prove that intermittent D+Q in humans causes clinically meaningful demyelination, and it certainly does not establish the magnitude of any human risk. The paper should update priors, but not be overread as direct human evidence. (EurekAlert!)
A second limitation is that D+Q is a drug combination, so attribution is incomplete unless the paper separately disentangles dasatinib alone, quercetin alone, dose-response, schedule, brain exposure, and reversibility. From the snippets I could verify, the headline result is the combination effect; I could not confirm from accessible sources how fully the paper decomposes which component drives the damage or whether the effect depends on a particular regimen. That matters a great deal because dasatinib is a potent kinase inhibitor with known off-target biology. (PNAS)
A third limitation is that the mechanistic language may outrun the evidence. “Cells reverted to a juvenile form because energy pathways were choked off” is plausible, but from the accessible material it looks more like a mechanistic model supported by transcriptional/metabolic clues than a definitively proven causal chain. To prove that strongly, one would want rescue experiments showing that restoring the implicated metabolic pathway prevents demyelination. I could not confirm such rescue data from the available sources. (Medical Xpress)
A fourth limitation is anatomical scope. The accessible summaries emphasize the corpus callosum. That is an important tract, but it leaves open whether this is a broad CNS white-matter phenomenon, a regionally selective vulnerability, or something tied to high-demand callosal oligodendrocytes. Without wider mapping, generalization is limited. (PNAS)
A fifth limitation is translational ambiguity around dose and schedule. D+Q is often used intermittently in senolytic paradigms, and toxicity can depend heavily on exposure pattern. Unless mouse exposures are benchmarked against realistic human CNS exposure, it is hard to know how alarming the result should be for human users. The accessible materials do not let me verify that bridge in detail. (ClinicalTrials)
My overall take is that this is an important cautionary paper, and probably a real advance, because it challenges the lazy assumption that senolytic interventions are directionally beneficial across tissues. The study appears especially valuable for showing that D+Q may damage a highly specialized, metabolically demanding CNS cell type even while being pursued as an anti-aging therapy. (PNAS)
But it is not yet a final verdict on D+Q in humans. The strongest justified conclusion is:
In mice, this paper provides evidence that D+Q can impair oligodendrocytes and reduce myelin in the corpus callosum, raising a serious safety concern for brain white matter that deserves close follow-up before broad prophylactic use. (PNAS)
If you want, I can also do a second pass in a more technical format with headings like background / methods inferred / key results / mechanistic interpretation / translational implications / weaknesses.
More likely D than Q but can this be explored?
Just a heads-up, as I’ve mentioned before: I’d suggest staying away from senolytic activators. I had some really serious health setbacks with the Life Extension version. Even when I scaled back the frequency to match clinical trial protocols, it didn’t help. The reality is that current senolytics just aren’t targeted enough yet—they end up killing healthy cells too.
Agreed. More recent finding, most preclinical, suggest we could be too clever by half taking this approach. I was exhausted for a couple of days after my last 2-day cocktail. I think I’ll wait for better evidence.
Was the dosage daily? There is no indication of frequency in the writeup.
Yes. And I think I’d like a near final verdict (of “no harm”) before taking an anti-cancer pharmaceutical as a preventive to aging. D + Q has always seemed nuts to me.
Is there proven benefits of D&Q in humans that outweighs this risk?
I generally don’t like articles from SciTech Daily because I find it hard to verify what they say. In this case I tried to get a clear answer with ChatGPT. I asked for a summary of the article, then a summary of the actual study the article referenced. In the process ChatGPT found this research: https://link.springer.com/article/10.1186/s12974-025-03425-3 with the title " Senescent cell reduction does not improve recovery in mice under experimental autoimmune encephalomyelitis (EAE) induced demyelination."
ChatGPT’s interpretation of the SciTech Daily article:
The SciTechDaily article is likely doing a secondary interpretation, combining:
But importantly:
Well, I’m just a guy with a computer, no medical training and access to an AI chat program that sometimes hallucinates. But, excluding my noted deficits, that last bullet point sums it up for me.
The article cited by SciTechDaily is ‘Senolytic treatment induces oligodendrocyte dysfunction and demyelination in the corpus callosum.’ Your AI hallucinated again; furthermore, without SciTechDaily’s interpretation, you would only be able to view the abstract, as the full text requires institutional access.
Furthermore, you need to upload the PDF to the AI to get a quality response. Seriously, don’t look down on SciTechDaily—the quality of your AI-generated answers is far lower than theirs. The administrator posted a guide on how to properly use AI; you’d better go and learn from it.
Wow! You seem to be a little touchy about my post! I didn’t mean to upset you. It’s just one person’s opinion like many others on this site.
The study emerged from efforts to test whether D+Q could rejuvenate myelin-producing oligodendrocytes in multiple sclerosis (MS) models. Instead, it revealed unexpected neuropathology in healthy brains. Crocker’s team used C57BL/6J mice—young (3-4 months or 6-9 months) and aged (22 months)—administering standard D+Q doses (dasatinib 5 mg/kg + quercetin 50 mg/kg, typically intermittent). They examined the corpus callosum, a white matter tract connecting brain hemispheres essential for cognition and motor control.
Probably the Dasatinib
I am quite wary of senolytics after self experiments with high dose fisetin in olive oil may have precipitated an umbilical hernia. This was around 2 or 3 grams of the stuff for a couple of days every three weeks, but soon after the third round…
I really wish people would stop with the D+Q.
It’s gonna be a while before it’s published (finishing data, publication) but we see no change in senescence whatsoever aside from people with super high levels. Fisetin is similar. Effects at best are marginal but the risks are all there
The pharmacological combination of dasatinib and quercetin (D+Q) has gained significant traction as a senolytic therapy designed to clear senescent cells and extend healthspan. However, recent data reveal a severe, unintended consequence: D+Q administration induces profound demyelination within the central nervous system (CNS) of both young and aged healthy subjects.
In this study, naive young (3–4 months) and aged (22 months) wild-type C57BL6/J mice were administered intermittent oral doses of D+Q (5 mg/kg dasatinib, 50 mg/kg quercetin) over four weeks. Transmission electron microscopy and luxol fast blue staining revealed significant loss of compact myelin specifically localized to the rostral corpus callosum. Strikingly, this demyelination was not driven by cellular toxicity; TUNEL and lactate dehydrogenase (LDH) assays confirmed that D+Q did not induce oligodendrocyte or oligodendrocyte progenitor cell (OPC) death in vivo or in vitro.
Instead, the senolytic cocktail triggered severe oligodendrocyte dysfunction. In vitro tracking showed that mature oligodendrocytes treated with D+Q underwent rapid morphological simplification and active process retraction within 24 hours. Concurrent bulk RNA sequencing of treated cells identified a massive transcriptomic shift, heavily upregulating the Unfolded Protein Response (UPR) and endoplasmic reticulum (ER) stress pathways. Key UPR genes, including ATF4, XBP1, and HSPA5 (BiP), were significantly overexpressed, a finding validated by immunohistochemistry in the demyelinated brain regions of treated mice.
The activation of the PERK-ATF4 pathway likely initiates a global translation block to manage ER stress, thereby crippling the oligodendrocyte’s capacity to synthesize the massive volume of proteins and lipids required to maintain the myelin sheath. Furthermore, D+Q treatment downregulated transcripts essential for mRNA transport (such as hnRNPs and Kif1b), impairing the local translation of myelin basic protein (MBP) at the distal cellular extensions.
These findings issue a stark warning for the translational application of D+Q in healthy individuals or prophylactic longevity regimens. The data strongly suggest that the mechanisms deployed to clear senescent cells simultaneously inflict critical structural damage to myelinating glia. [Confidence: High]
Source:
The pathology is driven by profound ER stress rather than direct cytotoxicity.
Protein Synthesis & mTOR: Oligodendrocytes are uniquely vulnerable to translational blocks due to the sheer mass of myelin they must maintain. D+Q treatment heavily activated the UPR (ATF4, XBP1, DDIT3/CHOP). The PERK-dependent UPR pathway limits eukaryotic translation initiation (eIF2-alpha phosphorylation) to clear misfolded proteins. This essential “survival” mechanism halts the synthesis of critical structural proteins, causing the myelin sheaths to collapse.
Autophagy & Cellular Senescence: Ingenuity Pathway Analysis (IPA) of bulk RNA sequencing predicted strong activation of macroautophagy pathways alongside the UPR. While autophagy is generally considered a pro-longevity mechanism, hyperactivation in the context of D+Q toxicity likely drives the rapid breakdown and retraction of existing myelin processes observed during live cell imaging.
Targeted Vulnerability: The pathology is distinctly localized to the rostral corpus callosum, mirroring localized demyelination observed in specific chemotherapy-induced cognitive impairment models (e.g., methotrexate). The biological reason for this regional susceptibility remains uncharacterized. [Confidence: Medium]
Historically, D+Q has been championed for its targeted clearance of senescent cells to alleviate systemic inflammatory burden. This paper identifies an organ-specific, off-target pathology: D+Q directly harms healthy, functional myelinating glia in vivo. It introduces a novel framework for chemically inducing MS-like “stressed oligodendrocyte” phenotypes (demyelination via process retraction, not apoptosis) in non-autoimmune models.
Methodological Weakness: The in vivo N-numbers are precariously low (N=3 for the primary electron microscopy data). Drawing broad translational conclusions from such a statistically fragile sample size is risky.
Missing Variables: The researchers failed to report the sex of the mice, obscuring potential sex-dimorphic responses to senolytics.
Translational Uncertainty: Dosing (5 mg/kg dasatinib, 50 mg/kg quercetin) was delivered via oral gavage. It is unclear how this murine pharmacokinetic profile scales to human equivalent doses currently utilized in clinical biohacking protocols.
Longitudinal Gaps: The study terminated at 4 weeks. There is no data indicating whether the demyelination is a transient, reversible shock or a permanent structural deficit.
Part 3: Claims & Verification
Claim 1: D+Q senolytics induce significant demyelination in the central nervous system (corpus callosum) without causing oligodendrocyte cell death.
Claim 2: D+Q directly inhibits oligodendrocyte progenitor cell (OPC) differentiation and forces mature oligodendrocytes into an immature, structurally simplified state.
Claim 3: D+Q toxicity in myelinating cells is mediated by the induction of severe endoplasmic reticulum (ER) stress and the Unfolded Protein Response (UPR).
Claim 4: Senolytics (specifically D+Q) decrease senescent cells in humans, making them a viable therapeutic strategy.
Human Equivalent Dose (HED): Using the FDA’s standard Body Surface Area (BSA) normalization (Mouse Km = 3, Human Km = 37, Ratio = 0.081):
Pharmacokinetics (PK/PD):
Safety & Toxicity:
Very happy to see you here. Could you answer a couple of questions about fisetin?
The general notion floating around is that it’s safe but ineffective. However, this seems to be based on a low daily dose. And even at higher doses, it’s known to be absorbed poorly. It would seem that its effectiveness hasn’t been fairly evaluated at high intermittent doses with enhanced absorption.
On another thread here, we got some AI feedback on increasing fisetin absorption using a homemade version of FF-20, approximating its amounts of fenugreek and sunflower lecithin and adding some fat or oil.
What’s your opinion regarding safety and effectiveness of high dose fisetin (via greater absorption with the kinda FF-20) when taken intermittently (for example, three consecutive days per month for five months)?
I haven’t seen anyone address this and doubt there have been any studies on it, even in mice. It seems the only thing studied has been daily dosing without the absorption enhancement.
In one of your videos, the risk of cancer due to fewer senescent cells was mentioned. Any other safety concerns with fisetin?
Anything you could share would be greatly appreciated.
I don’t overly trust SciTech Daily either. Nor do I totally trust A.I. at this point.