Substack has a Nazi problem AND a health disinformation problem

Substack creators and Substack audiences are supporting a platform that profits off of promoting dangerous antiscience content – at the expense of public health.

The Media and Democracy Project (MAD) is increasingly alarmed at the worrisome direction that Substack is taking. MAD recognizes the importance (and influence) of media ownership in all our work – which is why we are sounding additional warnings about Substack.

Key Takeaways:

• We report below how Substack “platforms, profits from and promotes” a significant number of dangerous health disinformation influencers

• Substack is aggressively building a media ecosystem that promotes audience growth of antiscience influencers via multiple mechanisms, including algorithms, “leaderboards” and search results

• Substack leadership has insisted on a hands-off approach to content moderation, including explicitly Nazi and White nationalist content

• Until Substack leadership publicly addresses its promotion and its profiting from both “Nazi” and antiscience health disinformation content – creators on the platform ought to revisit their presence on and promotion of Substack

• We outline below several actions that Substack, larger audience creators, and individual subscribers can take

Substack might be a transient oasis for creators

The information landscape is undergoing rapid transformation amid changing economics. It is increasingly dominated by a few corporate entities in contraction mode. All this combined has led many prominent journalists and creators to go out on their own, with a large portion of those people landing on Substack. While many admirable Substack creators are successful and have found refuge on the platform, we are increasingly concerned about the ethics and agendas of its leadership and ownership.

More than a Nazi problem: “Health Politics”

Substack has a well-documented history of platforming and even sometimes promoting literal Nazis and White nationalists. After threats by some prominent Substackers to leave the platform (some did), and a November 2023 article by Jonathan Katz in The Atlantic on Substack’s having a “Nazi problem”, Substack did remove a few accounts but mostly doubled down and said it would not remove extremist accounts including those with Nazi imagery unless they “incited violence”.

We have found that Substack has a health disinformation problem too, as it is profiting from and promoting this sometimes dangerous content. Substack platforms – profits from and promotes – dangerous public health disinformation, most obviously anti-vaccine disinformation. Substack is a media ecosystem where the antiscience movement has established an underappreciated, sizable, strong (and profitable) presence. Substack must be considered a battleground in the war on science. Writing in The Guardian in Sept 2025, Michael Mann and Dr. Peter Hotez describe the larger war on science “... science in modern societies is under siege from an even more insidious “antiscience virus” of weaponised disinformation.”

The inspiration for this report came from the 2025 Nazi Substack push email fiasco, when a member of the Media and Democracy Project visited Substack to check out the ruckus [visiting as a “new user” who did not subscribe] and had pro-Nazi Substacks promoted to him on a subsequent unrelated Substack search.

First the account of the “Mad American Stacker,” which posts and re-posts virulently racist – and anti-Semitic content, including posts that implicitly suggests violence. That would seem to go against even Substack’s tepid commitment to removing accounts that “incite violence.”

Notably some of the same racist bloggers also promoted clearly dangerous health misinformation. This led us down the rabbit hole of the Substack category of “Health Politics”.

Substack promotes accounts that push dangerous antiscience health misinformation

Substack is promoting, normalizing, and spreading dangerous health mis/disinformation to a larger audience – even those not seeking it out. We have observed multiple ways that Substack promotes antiscience health misinformation:

1- “HEALTH POLITICS” CATEGORY. Substack leadership has created and prominently features “Health Politics.” It is a category primarily used by antiscience creators. In practice, the term “health politics” is a euphemism for accounts that heavily promote conspiracy and anti-vaccination disinformation, and peddle unproven (and some dangerous) cures such as ivermectin. Many promote right-wing politics fused with a rejection-of-science worldview. Many of these accounts also seem to have a grift component as they offer commercial advice on buying dewormers, chemicals that may “cure cancer,” and/or shill for gold, silver, and crypto. Nearly all of the paid-subscriber top 10 “Health Politics” leaders are newsletters either dominated by health mis/disinformation or heavily interspersed with it. We use the terms “misinformation” for some of the content that may be unintentionally not factual or supported by science - and “disinformation” for content that is false and deceives and undermines trust in science or for financial gain. It is an affront to public health and the common good for Substack to gleefully refer to these content creators as “Bestsellers” of potentially harmful information. Substack leaders anointing this category as “Health” implies credibility and value. Explore this category for yourself: https://substack.com/leaderboard/health-politics/paid

This Substack category is neither “health” nor “politics”. It is heavily antiscience misinformation and disinformation, often promoting false cures and peddling remedies and advice such as “DMSO,” “chlorine dioxide,” animal de-wormers (including ivermectin), and heavily anti-vaccination. There is often an anti-government political agenda to these accounts and they further erode trust in expertise, science, democracy, and the common good.

2- NEW SUBSCRIBERS. Even without seeking out “Health Politics” content the Substack algorithm (possibly based on “Bestseller” numbers) promotes engagement with health misinformation content. For some potential new subscribers (we tested on multiple devices simultaneously in three cities that had never visited Substack before), “Health Politics” was a category recommended. In one instance the #2 recommended Substack after Substack’s own blog was “The Truth About Cancer.” That newsletter, which has 1.1+ million subscribers, a panoply of conspiracy theories including claiming the polio vaccine (!!!) didn’t really do much good, that the CDC created an autism cover-up, and that the Texas floods in the summer of 2025 may have been engineered.

3- WEBSITE/APP LAYOUT: All visitors and subscribers see the “Leaderboards” of Substack newsletters on a menu bar that prominently features the “Health Politics” category. It is the #10 Category on Substack’s category menu with “Science” being #16 and “Health and Wellness” at #19 (the latter two are also more difficult to find as they require additional clicking or scrolling on most devices). Substack states that “Leaderboards bring the Substack ecosystem to life by helping writers and creators find new peers, potential collaborators, and inspiration. Audiences, meanwhile, can browse the leaderboard to discover compelling new voices.” And “Top Bestseller – This view highlights the highest-earning publications in their category, ranked by Annual Recurring Revenue (ARR). It recognizes the consistent effort, quality, and subscriber loyalty required to build a sustainable, high-revenue business on Substack.” The antiscience category is dangerous to public health and should hardly be elevated to such prominence and prestige based on purported paid subscribers.

One example is this AI video of RFK Jr. fighting Dr. Anthony Fauci.

The list of creators spreading dangerous public health disinformation on Substack’s “Leaderboard” has some of the same names as the 2021 report on the biggest spreaders of disinformation by the Center for Countering Disinformation and Hate.

In January 2022, Elizabeth Dwoskin wrote in the Washington Post about Substack profiting from misinformation and anti-vaxxers who had been banned from other platforms such as Facebook, YouTube or Twitter (pre-Elon Musk takeover) shifting to Substack; and in April of that year, the New York Times discussed anti-vaxxer Robert Malone having 134,000 Substack subscribers, including roughly 8,000 paid subscribers – and in 2025 has nearly tripled to 356,000 subscribers. Substack put out a statement in late January 2022, saying, in part, “An important principle for us is defending free expression, even for stuff we personally dislike or disagree with.” But what if Substack creators are putting out false information that will physically harm people? Isn’t there an uncrossable line somewhere? It is objective reality that COVID vaccines did not kill more people than the COVID-19 virus.

4- SUBSTACK ALGORITHMS: In the summer of 2025, Substack sent a push alert promoting a white supremacist blog, NatSoc, with Nazi imagery including a swastika as its header. Marisa Kabas and Jonathan Katz wrote a piece on the extremism continuing to flow on Substack. They note that the bestselling “History” newsletter is by Darryl Cooper, a Nazi sympathizer who called the Holocaust “humane” – he has 184,000 subscribers, including tens of thousands that are paid, of which Substack collects a 10% fee. Substack co-founder Mackenzie has promoted Cooper in the past.

It is likely that Substack is sending push alerts of “Health Politics” content. Substack prides itself on helping creators expand their subscribers – “Recommendations from your substacks”, push notifications etc. The extent to which Substack has contributed to the financial and audience growth of creators promoting health misinformation use it is unknown. Per Substack “Today, more than 30% of all new free subscriptions and around 10% of paid subscriptions to Substacks come from within our network.”

The RFK Jr./”MAHA” movement, which has decimated the CDC and NIH, is prominently represented on Substack. Most of the top 10 “Health Politics” newsletters on Substack when we checked on August 29^th and again November 20^th 2025 are some combination of anti-COVID vaccine, anti-vaccine in general, misinformation about the dangers of anti-depressants, the benefits of anti-parasite drugs approved for animal use, the benefits of “natural” solutions that predate modern medicine and other musings that are in many cases would dangerous to those who follow them. The “Bestsellers” lists on “Science” and “Health & Wellness” are much less worrisome to people’s health than the “Health Politics” ones, with a mix of misinformation, people vibe-posting and actual, medical- and science-based knowledge from credible people such as Dr. Eric Topol (Ground Truths) and Katelyn Jetamina (Your Local Epidemiologist) and Dr. Jen Gunter (The Vajenta).

SUBSTACK ALGORITHM SEARCH RESULTS:

Hazardous “Health Politics” creators are prioritized as top results using the Substack search function:

The Problematic “3 P’s”: Substack platforms, profits from, and promotes health misinformation influencers. The explanations by Substack leadership – “freedom of expression” rationale ignores the main problem: they promote and profit from that “expression”. They are not merely a neutral host – they are actively engaged in helping accounts with antiscience disinformation with audience growth.

How much does Substack make from health misinformation accounts?

We don’t know, but the top 10 “Bestsellers” have more than two million subscribers. The public would welcome Substack revealing what the “Health Politics” leaders earn; we’ve attempted to approximate what Substack earns from them (and helps these creators earn): Assuming a 5% conversion to paying subscribers at a hypothetical $7/month that’d be almost $1 million a year (as of 11/20/25 the average annual subscription fees for the top 10 average $101/year). That’s private profit for the misinformation peddlers and for Substack. And that pursuit of profit in misinformation very likely harms public health.

A cloudy future. Silicon Valley. Substack is a privately-held company that has established itself as a dominant media platform. In July 2025 Substack announced a new $100 million round of funding with participation again by Andreessen-Horowitz, a VC firm whose co-founder Marc Andreessen is outspoken in support of right-wing politicians and causes. What will that funding mean, and what influence might be attached to it? Even before the latest round of funding, Dave Troy had written on how creators on Substack may be “inadvertently” contributing to the U.S.’s dismantling. As government experts at top health organizations get ousted in favor of loyalists and anti-vaxxers, it becomes even more urgent for people to reconsider supporting an outlet that is propping up health misinformation – Substack – with their time, attention, and subscription dollars. Those who draw readers – and paychecks – on Substack should also consider whether to continue contributing to the Substack ecosystem or whether to move to Ghost, Beehiiv, Medium, a self-hosted option or other. One writer who recently moved, David Farrier, discussed his reasoning here. For a particularly critical assessment of the Substack model read this by Beehiiv cofounder Tyler Dank “Substack has become the Amazon of publishing. It offers the consensual hallucination of independence and ownership while deceivingly consolidating control and dictating the terms of success for sellers (i.e. you, the writers).”

Any social media platform using algorithms will have content moderation challenges – yet there’s a difference in some disinformation and hate speech evading notice, at least for some period of time, and in the platform not even trying to remove it or actually serving it up as content you might want to see. Algorithms expose the weakness of free speech “all-but-absolutism” allowing promotion of lies, abuse, and overt biases – and contribute to radicalization. And on social media platforms (which Substack is) where algorithms help decide what people see (e.g. search results and recommendations, pushing accounts or content that is flush with known falsehoods is dangerous. German writer Joachim Klement wrote of the dangers of free speech absolutism in early 2023, citing among other things, a sharp increase in support for Nazis once the Nazis took over the radio broadcasts.

What are we going to do?

The leadership (and ownership) of Substack have made increasingly clear their priorities, ethics, and agenda. Substack co-founder Hamish McKenzie has hosted eugenics supporter Richard Hanania on a podcast, and while he said he didn’t know of Hanania’s expression of racist views when he had him on; he also said he didn’t regret inviting Hanania. We see publishing our work on a platform as an endorsement of the platform and its values. We do not want to use our credibility and social capital to whitewash a platform that prioritizes “hate-for-profit” and promoting public health misinformation.

We consider this post an alert and share our concerns about the future. Yes, we know it’s less than optimal that we are writing this to you on Substack, however because of these systemic concerns, the Media and Democracy Project plans to transition off of the platform. It’s a dilemma that any platform you don’t own can shift with the business or political or ideological interests of owners/management. And oftentimes on social media (which Substack has become), the algorithms favors the most extreme and most polarizing and engaging viewpoints, many of which are not based in facts. Yet a platform such as Substack makes it simple for writers to set up shop, to reach a large audience – it passed 5 million paid subscriptions by March, to reach new readers via Substack recommendations or in the app, and to collect payment. We sympathize with the thousands of creators needing to monetize and build communities; however, that Substack is making money and building its user numbers off engagement driven by white supremacy and antiscience disinformation – some of which is being promoted by its own algorithms – has become untenable for our community. It is one thing to allow it, something else to profit off it, and even more problematic to promote it. Substack’s “free-speech absolutist” founders are entitled to their amoral corporate “growth-at-all-costs” philosophy but we think that growing our audience around a platform that does not promote and profit from hate — or from undermining public health — is fundamental. We think the responses of Substack leadership to previous criticisms are inadequate and ominous.

What should Substack do to address its antiscience and health misinformation problem?

1 – Acknowledge publicly that both promoting and profiting from health mis/disinformation content (such as subverting vaccines and cancer “cures”) is distinct from “platforming.” It is not clear to us the distinction between the current Substack policy of deplatforming hate speech that “incites violence” while having no policy to remove speech that stochastically sabotages public health (likely contributing to physical harm and/or death).

2 – Conduct a review of the “Health Politics” category and remove established and habitual antiscience influencers. Substack is a private company and has the power to refuse to host (and amplify) Nazis and peddlers of antiscience https://substack.com/content; this is not a First Amendment issue.

3 – “Health Politics” is a euphemism and blurs dangerous content with an actual field of study. Stop using this term and stop promoting it as a topic to new users of their platform.

4 – Make reporting and deplatforming dangerous health mis/disinformation easier and create moderation of content or develop a labeling system with warnings. However, outsourcing large scale moderation to the platform and to individuals is a dereliction of duty of ownership. The “Report to Substack” menu is evolving and should include an option for health disinformation” which is arguably more harmful than “pornography.”

Creators and Subscribers:

1 – It is essential to keep supporting journalists and pro-democracy voices on Substack – however consider donating to them directly rather than with your Substack subscription.

2 – Stop calling posts “Substacks”, instead call them “blogs.” Substack is a brand. Stop doing PR for the Substack brand. Read Anil Dash’s “Don’t Call It A Substack” “...the reason Substack wants you to call your creative work by their brand name is because they control your audience and distribution.“

3 – We encourage the largest pro-democracy and journalism accounts to form a coalition to demand changes or threaten to take their audiences elsewhere. You have influence that you should use and will be strongest collectively.

4 – Start working on a backup plan. How can you take your community and your work elsewhere? Where would you go? Have you downloaded a spreadsheet of your subscribers and paid supporters? What happens if another shoe drops and Substack leadership makes an executive decision that demonstrates they have an agenda at odds with your values?

Thank you for reading and sharing this blog post. We will keep you updated.

Share your thoughts with us below or by email: info@mediaanddemocracyproject.org

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