Importance The usage of social media is associated with worsening perceptions of body image and increasing access to, and use of, toxic weight loss supplements. Little is known about the effect of nonlethal doses of one mechanistically unique supplement, 2,4-dinitrophenol (DNP). DNP has been banned by the FDA making human studies difficult, but the public still consumes DNP leading to a gap in our knowledge on the effects of DNP. Here we use social media to investigate the use of DNP, providing the largest characterization of its usage to date.

Objective Determine the doses of DNP generally consumed, adverse effects at those doses, and coingestants.

Design Cross-sectional analysis of Internet posts.

Setting Our study collected publicly available data from 2017–2018 from Internet discussion forums (also called bulletin boards) dedicated to the discussion of weight loss and body building.

Participants Participants are anonymous posters on these Internet forums.

Main Measures Our main measure was the distribution of reported doses of DNP consumed. Our secondary measure was the frequency of adverse effects reported at those doses.

Results We collected 661 posts across 5 online forums. The most commonly ingested dose reported was 150 mg (1-2 pills, depending on formulation), followed by 300 mg (2-3 pills). The most commonly reported adverse effects were sweating and a sensation of warmth, followed by yellow discoloration of secretions. The most common coingestants were antihistamines, cetirizine and loratadine.

Conclusions and Relevance 2,4-dinitrophenol is a mechanistically unique weight loss agent reported to be associated with sweating and a sensation of warmth at the most commonly reported ingested doses. Common co-ingestants are antihistamines, although itching was not directly reported as a side effect. Coingestion of an antihistamine, which can lessen the body’s ability to dissipate heat, could worsen the side effects of DNP. This is the first formal description derived from social media of DNP usage at nonlethal doses. Further investigation is needed to determine the therapeutic index of DNP. Less toxic derivatives may provide a starting point for pharmacological adjuncts to weight-loss.

The authors have declared no competing interest.

This work received no specific funding.

All relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript.

Yes

All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.

Yes

All data are publicly available. All code for analysis is available on request.