Madison Area Lyme Support Group

https://treatlyme.com/guide/dapsone-lyme-persisters/

Updated: July 31, 2026

Horowitz Dapsone Protocols: Risks vs Benefits Explained

About Dapsone & Persisters

Dapsone, a Leprosy drug, can help some with treatment-resistant Lyme and Bartonella due to persisters plus treatment resistant Babesia. In 2016, Richard Horowitz, MD, and Phyllis Freeman, PhD, published research on 100 patients. The study showed 59 percent of people had improvements with dapsone of 100 mg or less.

More recently, Dr. Horowitz has continued refining a higher-dose approach, publishing a more detailed double-dose/high-dose protocol in 2023.

However, my experience with dapsone is mixed. While it helps some, it is also a very difficult medicine for many to take.

In this article, I review:

• my experience with this novel medicine,
• a specific antibiotic protocol that includes dapsone as a normal-dose regimen,
• how to decrease side effects and Herxheimer reactions on dapsone,
• the risks of using dapsone,
• the chances for treatment success using a dapsone regimen, and
• a detailed look at, and critique of, Dr. Horowitz’s newer double-dose/high-dose protocol and why I don’t support it.

(See link for video and article)

_______________

**Comment**

I always appreciate doctors who share their clinical experience. It’s sometimes the only way we can gather intel on whether or not we should try a certain treatment. Case in point – I wrote about my severe psychosis after taking disulfiram, followed by another practitioner’s experiences in ameliorating symptoms as well as an update on a few points of consideration.

So, while Dapsone may be a perfect fit for some, it may not for others.

This is another point that never makes the news. Reactions to treatment varies widely in Lymeland, probably because some have been infected for years and their bodies are simply overwhelmed, making another drug appear to be a toxin by the body.

Dr. Ross points out the following issues:

• You shouldn’t take Dapsone if your G6PD levels are low.
• Dapsone blocks folate metabolism which can lead to anemia
• Dapsone suppressed bone marrow which can also lead to anemia
• Dapsone is a harsh drug that causes severe herxes, allergic rash, methemoglobinemia, and many side effects

The article contains Horowitz’s 2016 Dapsone regimen. Ross states he does not recommend the Dought or high dose Dapsone protocol and doesn’t offer it in his practice. He also points out that Horowitz’s 2023 paper which offered HDDCT to 50 patients, but only 25 are considered in the results leaving one to ask how many dropped out due to side effects. Further, Horowitz is the treating physician, the sole study author, and one of three others from his practice who performed the validation and analysis. There was no control group, no blinding, no independent review, and no oversight.

Ross does feel; however, that some sho failed other treatments could consider the normal-dose dapsone 100mg protocol if carefully monitored.

For more:

• https://madisonarealymesupportgroup.com/2016/05/09/leprosy-drug-for-lyme/
• https://madisonarealymesupportgroup.com/2016/10/09/mycobacterium-drugs-for-ld/
• https://madisonarealymesupportgroup.com/2022/06/22/efficacy-of-short-term-high-dose-pulsed-dapsone-combination-therapy-in-the-treatment-of-chronic-lyme-disease-post-treatment-lyme-disease-syndrome-ptlds-associated-coinfections-a-report-of-3-c/
• https://madisonarealymesupportgroup.com/2020/10/01/new-dapsone-study-breaking-biofilm/
• https://madisonarealymesupportgroup.com/2020/12/08/dapsone-for-lyme-4th-annual-lyme-disease-in-the-era-of-precision-medicine-conference/