I read Dr Joseph Mercola with cautious interest. His work occupies a space between honest medical dissent and persuasive alternative marketing. One moment he is drawing attention to real flaws in pharmaceutical orthodoxy; the next, he seems to imply that a nearly forgotten industrial solvent could be the key to surviving cancer. His latest article, on DMSO—dimethyl sulfoxide—is a perfect example. It mixes truth, hope, and a faint smell of garlic. That last part, of course, is literal. DMSO famously causes the body to emit a sulphurous odour once absorbed.

In his 4 April 2025 article, Mercola argues that DMSO is a safe, inexpensive, and largely ignored compound that could ease the “invisible burdens” of cancer—fatigue, chronic pain, anxiety, and the physical toll of chemotherapy and radiotherapy. His core claims include:

1. DMSO reduces oxidative stress and inflammation – Mercola cites its antioxidant properties, pointing to studies showing reduced lipid peroxidation and cytokine activity in preclinical models 1.
2. DMSO protects healthy tissue during radiation therapy – He refers to animal studies showing that DMSO applied before radiation exposure reduces mucosal injury 2.
3. DMSO may influence cancer cell behaviour – Some studies suggest that DMSO can induce differentiation in certain malignant cells, causing them to behave more like normal tissue 3.
4. DMSO can carry therapeutic agents through membranes – It penetrates the skin and other barriers, allowing it to serve as a delivery agent for drugs or natural compounds 4.
5. Its neglect is politically motivated – According to Mercola, DMSO’s low cost and off-patent status make it unprofitable and thus unattractive to the pharmaceutical industry, which he implies is colluding with regulators to keep it from wider use.

The tone is classic Mercola: adversarial towards the establishment, deferential towards personal experience, and rich in medical citations—but always leaning heavily on the reader’s distrust of authority.

Many of Mercola’s references are real. Studies do show that DMSO has remarkable properties, including:

• Anti-inflammatory effects: DMSO scavenges hydroxyl radicals and suppresses IL-6 and TNF-α in inflamed tissue 1.
• Radioprotective properties: A 2019 study found that DMSO reduced oral mucositis in irradiated mice by mitigating oxidative and inflammatory pathways 2.
• Cell differentiation: DMSO has long been used in cell culture to induce differentiation in myeloid leukaemia cells 3.
• Drug delivery: Its membrane penetration is well documented. This makes it both promising and dangerous—it can carry toxic substances across barriers that are normally protective 4.

That said, very few of these studies involve humans, and almost none involve cancer patients directly. The FDA has only approved DMSO for one condition: interstitial cystitis, a painful bladder disorder 5. Every other use remains experimental or unapproved.

Moreover, DMSO comes with risks. At high concentrations, it can cause nausea, skin blistering, altered liver enzymes, and unpredictable interactions with other drugs. Because it drags molecules across the skin barrier, it can deliver contaminants, pathogens, or unintended chemicals straight into the bloodstream 6.

So while Mercola is correct that DMSO has untapped potential, he is far too confident about its safety in clinical use. The evidence simply isn’t there yet.

Mercola’s medical populism follows a familiar pattern. He presents DMSO as a humble and effective solution, kept out of reach not because it fails, but because it threatens profit. There may be some truth to this. The structure of modern medicine undeniably disfavours unpatentable compounds. But Mercola’s conclusion—that DMSO’s obscurity is the product of a coordinated suppression effort—is a leap too far. It overlooks a simpler explanation: caution.

The medical establishment is not always wise, but it does move slowly for a reason. New treatments must be tested, not just hoped into being. Patients are fragile. Cancer patients especially. And while DMSO may help in some cases, it may also cause harm. To endorse it based on early-stage studies and anecdote is not bold. It is irresponsible. Everything Dr Mercola has said about the terrible vaccines we were almost forced to take can be said equally well about some of his miracle cures.

I am not defending the pharmaceutical industry’s worst habits. Its influence over research, publication, and regulation is profound and often perverse. But our task should be to reform that system—not abandon the disciplines of science in favour of YouTube testimonials.

Mercola is not wrong to ask why so many promising compounds are never developed. But he is wrong to imply that DMSO, as it now stands, is ready to sit alongside radiation or immunotherapy. The studies he cites should encourage further research, not early adoption.

There is a difference between being open-minded and being credulous. We need more of the former and much less of the latter.

DMSO may one day become a valuable adjunct in cancer care. Its pain-relieving and radioprotective effects are worth studying. But the leap from laboratory finding to therapeutic use is enormous, and Mercola’s enthusiasm is premature. He is not wholly wrong—but neither is he a guide to be trusted without scrutiny.

DMSO, like Mercola himself, lives in a twilight space between promising science and premature evangelism. That space is worth exploring. But it is not a place to build a new standard of care.

References

1. Santos NC, et al. (2003). Biophysical studies of DMSO effects on lipid membranes. Biochim Biophys Acta.
2. Chen Y, et al. (2019). DMSO alleviates radiation-induced oral mucositis in a murine model. Int J Radiat Oncol Biol Phys.
3. Collins SJ, et al. (1978). Induction of differentiation of human promyelocytic leukemia cells by DMSO. Cancer Res.
4. Jacob SW, et al. (1982). The Miracle of DMSO. New York: William Morrow.
5. U.S. Food and Drug Administration (2021). Approved Drugs: DMSO (Rimso-50).
6. WebMD. (2024). DMSO: Uses and Risks. Retrieved from https://www.webmd.com/vitamins/ai/ingredientmono-874/dmso