It is a common saying in the publishing industry that the relationship between advertising and journalism should be like Church and State: always separated. This cliché, however, has been challenged by news outlets' growing adoption of content recommendation platforms . These tools display blocks of "native" ads that mimic the layout and language of news articles, blurring the lines between journalism and advertising.
However, this is not the only issue in this industry. A new investigation by Aos Fatos, detailed in this report, reveals that 9 out of 10 native health ads on major Brazilian websites are misleading. Falsely promoting the cure for severe diseases such as diabetes and Alzheimer's, hiring actors to pose as doctors, and fabricating customer testimonials are some of the common misleading strategies identified.
Over six months of investigation, Aos Fatos analyzed more than 242,000 ads displayed in content recommendation boxes on nine of the most relevant Brazilian news websites that use this technology.
This initiative is part of the Check-up project, carried out by Aos Fatos and supported by Codesinfo — a program organized by Projor and sponsored by the Google News Initiative.
All collected ads, the code used to extract them, and the analysis methodology are available at the bottom of this page.
The main topics covered in the report are below.
- The report's key findings
- Nine out of 10 native health ads are misleading
- Common strategies used by disinformers
- What the platforms and publishers say
- How we collected and analyzed the data
The report's key findings
- Aos Fatos analyzed more than 242,000 native ads from nine Brazilian journalistic websites and fact-checked over 90,000 health ads;
- Nearly 90% of health-related ads contain false or distorted claims;
- Products promising to relieve pain (22%), weight loss (17%), and to treat diabetes (16%) are the most common among misleading ads;
- Advertisers use five recurring strategies to deceive consumers: fabricating or exaggerating the benefits of supplements; hiring fake doctors and experts to endorse products; creating fake testimonials from celebrities and anonymous clients; mimicking the visual identity of professional journalistic websites; and streaming long and rambling videos with suspenseful narratives to retain viewers.
Nine out of 10 native health ads are misleading
An investigation conducted by Aos Fatos reveals that 9 out of 10 native health ads on major Brazilian news sites are misleading. Out of 90,934 fact-checked ads, 81,447 (89.6%) contained false or distorted claims, earning the "false" or "misleading" labels according to Aos Fatos' methodology.
Most of these ads promote treatments that lack scientific validation, exaggerate supplements effects, or use fake testimonials attributed to clients, doctors, and celebrities. In some cases, they do not sell products but direct the readers to health articles with incorrect information.
Only 3.6% of the ads were classified as truthful, while 6.9% could not be fact-checked as they lacked objectively verifiable claims or were no longer online during the analysis.
Products for pain relief, weight loss, and diabetes dominate misleading ads
Within the misleading ads sample, products promising to relieve pain are the most common, appearing in 22% of the content. Products related to weight loss (17%), diabetes (16%), men's health (13%), and hearing (11%) come next.
The analysis further shows that misinformation in native ads affects all the websites and ad platforms selected.
The newspaper Folha de S.Paulo registered the highest proportion of misleading ads, 99%. The website of the magazineVeja had the lowest, 46%. The remaining seven publishers had rates above 80%, as shown in the chart below.
Among the platforms, 95% of Outbrain ads (Estadão newspaper) were misleading. The figure is 91% for Taboola and 46% for MGID (Veja).
What are native ads and content recommendation algorithms?
The IAB (International Advertising Bureau) defines native ads as a type of advertisement that "follows the design, location, and behavior of the environment in which it is embedded." For instance, a native ad in a search engine like Google resembles a search result. On Instagram, it mimics an organic post. On a journalistic website, it emulates the visual style and language of news articles.
One of the most widespread applications of this concept in the Brazilian publishing market is content recommendation boxes. These sections, usually located at the end of news articles, mix advertising inserts with calls to journalistic content, as shown in the example below.
Of the 100 most visited Brazilian news sites according to Similarweb, 62 use native ads platforms. The group includes traditional newspapers like Folha de S.Paulo, O Globo, and Estadão, as well as digital-native outlets like Metrópoles, Terra, and iG. Three advertising platforms dominate the market. Of the 62 websites, 35 (56%) use Taboola, 14 (22%) use Outbrain, and 8 (13%) use MGID.
Strategies used by disinformers
Aos Fatos analysis identified five recurring strategies advertisers adopt to deceive consumers.
1. Fabricating or exaggerating product benefits
One of the main strategies in misleading ads is fabricating or exaggerating the benefits of the advertised products. Dietary supplements are sold as cures for complex diseases, and everyday accessories are advertised as definitive solutions for chronic pain.
An example is ZumbiCalm, an oil allegedly invented by Pfizer. It promises to eliminate tinnitus and even restore hearing if used twice a day. In reality, as shown on its packaging, the product is merely a multivitamin unrelated to the pharmaceutical company.
The ZumbiCalm label specifies that it is a dietary supplement, but the advertisement promises hearing restoration — a claim prohibited by Anvisa (the Brazilian Health Regulatory Agency) for this type of product.
Other advertised supplements promise to cure diabetes, prevent Alzheimer's, reverse skin aging, solve intestinal problems, and prevent hair loss, among others.
For instance, an ad showcased on five outlets recommends a homemade solution that "reverses diabetes in 25 days," "stabilizes glucose," and "works almost like an insulin injection." According to the text, the "independent researcher" who developed the solution "encouraged his followers to resume eating carbohydrates regularly, including candies, pizza, and pasta."
According to Anvisa, the Brazilian legislation prohibits associating dietary supplements with the cure for diseases. "Under no circumstances can a dietary supplement indicate prevention, treatment, or cure for diseases. This type of claim is exclusive to medications," the agency's website states.
Other products like orthopedic shoes, knee braces, and posture correctors are marketed as miraculous cures that eliminate the need for traditional medical interventions such as surgeries or especialized follow-up treatments.
Marketed in Brazil as exclusive experts discoveries, these items are often resale of products imported from international retail websites, in which they are not classified as health products. One example is the Regal Comfort sandal, advertised as being designed by doctors. Actually, it is an ordinary shoe easily found on websites like Aliexpress, Amazon, and Shein.
2. The argument from (false) authority
Health-related native ads usually feature specialists endorsing cosmetic and health products. However, these endorsements are often fabricated: advertisers hire actors to pose as health professionals, manipulate stock images, and falsely claim the support of renowned researchers.
In the collected ads, there are cases in which the same person appears in videos for different products with different names and specialties. In the ads below, "Dr. Cleiton Albuquerque, PhD, Ophtalmology" promotes a supplement that claims to improve vision, while the "urologist and biologist" Lucas Fontana showcases the claimed benefits of a prostate product.
Some ads also use stock images as if they depict a specialist recommending the product. For example, the fictitious Dr. David González, allegedly affiliated with Cambridge University, endorses a product to treat varicose veins. A reverse image search reveals that the picture is a digitally altered version of a photo from Shutterstock.
There are also ads that associate the product with renowned researchers and studies that have never endorsed it. For example, a skincare product ad suggests its development was based on the research of Elizabeth Blackburn, a Nobel laureate in Medicine for her work on chromosomes and aging processes.
In an interview to the newspaper O Globo, Blackburn advises against miraculous products or supplements. She advocates that proper nutrition, reducing stress and exercising are the keys to healthy aging.
"Approved by Anvisa." Lastly, some misleading ads distort the regulation for dietary supplements set by Anvisa (the Brazilian Health Regulatory Agency), which merely allows selling this type of product. The advertisers suggest that the agency endorses the product in display and its miraculous claims.
This is the case of Trioderm+, a supplement claiming to resolve skin sagging and wrinkle formation. The ad references Anvisa's allegedly approval to support its claims. However, the regulatory agency explicitly states that supplements promising to reduce "wrinkles, cellulite, stretch marks, sagging" are irregular and advise against using them.
3. Fake testimonials from customers and celebrities
Similar to the fake medical endorsements, misleading ads falsify positive reviews from anonymous customers and celebrities.
The singer Simone Mendes, the TV host Ana Maria Braga, and the actor Susana Vieira are three of the celebrities featured in these ads. Depicted as satisfied customers of miraculous products, they have publicly refuted these ads.
Simone Mendes stated that a doctor supervised her weight loss journey and that she is suing brands that misuse her image. Ana Maria Braga declared she does not promote any cosmetics. Susana Vieira said in an interview that she has undergone cosmetic procedures and only uses imported cosmetics.
Regarding anonymous customers, advertisers create characters and use manipulated stock photos. In one example, an ad for a clarifying face cream claims that a customer named Renata used the product to remove skin blemishes. However, the image is a digitally manipulated version of a photo from Freepik.
In other cases, ads use photos of patients who got plastic surgeries as if they were the results of cosmetics and supplements.
4. Using journalistic language and symbols
By definition, all native ads on journalistic sites attempt to mimic the format of a news article. However, some misleading ones replicate the layout and typography of well-known portals to disguise deceptive advertising as trustworthy information.
In these ads, users are redirected to pages that copy elements from websites like g1, UOL, and R7. The goal is to make readers believe the content belongs to these portals and that the ad is actually a journalistic piece.
The confusion between news and advertising is further exacerbated when misleading health ads appear alongside articles covering the same topic.
For example, Estadão published an article about diabetes prevention, which appeared alongside a fake ad promising a cure for the disease. The journalistic text, translated from The New York Times, discussed how fiber intake can help reduce the risk of diabetes and other conditions. Meanwhile, the ad promoted a product claiming to cure diabetes "with just six drops."
5. Long and suspenseful videos
Long videos with no playback controls — such as pause, fast forward, or rewind — are another recurring strategy in misleading ads. They follow a standard script: they start by promising to reveal a miraculous and innovative solution at the end, but prevent viewers from skipping ahead.
Instead, the content drags on for many minutes, sometimes exceeding an hour. The narrator repeatedly asks the viewer to "wait just a little longer" and emphasizes that the "secret" will be soon unveiled, employing a strategy designed to keep the customer's attention.
During this time, viewers are subjected to narratives that evoke emotional discomfort and identification through embarrassment. The narrator often says they has dealt with a specific health or aesthetic condition, or has a personal connection to it. They describe situations of humiliation and suffering, in an attempt to create a bond with the viewer, who may feel ashamed for experiencing the same issue.
In addition to discomfort, the ad usually exposes viewers to other disinformation tactics cited in this report, such as fake doctors, misinterpretations of scientific research, fabricated testimonials, or results from other procedures being falsely attributed to the advertised product. They also present unrealistic or exaggerated promises of benefits.
Moreover, there is pressure to purchase the product, driven by a sense of urgency through phrases like "Act now, as stock is running out" or "Do this before it's too late." These elements create an experience designed to exploit consumer insecurities and push them toward buying the advertised product.
What the platforms and publishers say
Aos Fatos reached out to all the news outlets and ad platforms mentioned. Only Terra and Folha de S.Paulo responded. Below are their complete statements.
Terra
“Terra is a publisher that has been contributing to the Brazilian society for over 20 years by providing quality and responsible information. During this period, Terra has developed partnerships with platforms like Taboola for content distribution. Taboola has a delimited position on Terra, and the displayed articles reinforce that they are sponsored/paid inserts. Terra, in turn, curates and blocks inserts considered false or misleading and maintains contact with Taboola, which is responsible for capturing advertisers, to take further measures and block suspicious ads.”
Julio Tortorello, head of Monetization at Terra&VivoAds
Folha de S.Paulo
“Folha clarifies that it maintains strict procedures to block unauthorized ads. When an unauthorized ad is identified, it is immediately taken down.”
Vivian Kato, Digital Business Manager at Folha de S.Paulo
How we collected and analyzed the data
Analyzed websites
Aos Fatos selected the ten most-visited Brazilian news websites that use native ad platforms.
First, we identified the top 100 sites in Brazil in the "News and Media" segment between January and March 2024, according to Similarweb. Then, we manually verified the presence of native advertising boxes on them.
Some of the portals listed — globo.com, uol.com.br, and abril.com.br — host multiple sites. In these cases, only one subdomain per portal was included in the analysis: the websites of the newspaper O Globo (oglobo.globo.com), UOL News (noticias.uol.com.br), and of the magazineVeja (veja.abril.com.br).
Not all sites hosted on the same portal use the same ad platform. For example, g1, which is part of globo.com, does not use external ad platforms — while O Globo, from the same domain, uses Taboola. Similarly, UOL News uses UOL Ads, while the Folha de S.Paulo, from the same group, uses Taboola. Therefore, the conclusions of this report about one website do not automatically apply to other addresses within the same domain.
Data gathering
The process of scraping and automatically analyzing the data occurred in three stages.
From June 17 to July 30, 2024, a server accessed each domain multiple times daily and extracted the URLs of links on their homepages. The server then accessed each collected URL and, using the Playwright automation library, downloaded the texts and images of native ads found. In total, 15,164 unique URLs were extracted, and 242,812 ads were collected, as shown below.
Finally, using OpenAI's GPT-4 model, each ad was automatically classified into one of the following topics:
- Automotive
- Home and Garden
- Cooking and Gastronomy
- Education
- Fashion
- Family and Relationships
- Finance and Business
- Health and Beauty
- Technology
- Travel and Tourism
- Sports
- Politics
- Environment
- Culture and Arts
- Gambling
- Other
The graph below shows that Health and Beauty was the most popular category in the collected sample, accounting for 35.9% of the ads.
The source code for collecting and automatically analyzing the data is on the Aos Fatos GitHub repository. For this report, the server was georeferenced in São Paulo. Since programmatic ads consider the user's location and browsing history to decide which ads to display, different settings could lead to different results.
Fact-checking health ads
We fact-checked all the ads classified under Health and Beauty to verify whether the advertising claims were misleading.
The analysis followed the methodology outlined in Aos Fatos' editorial policy. There are three main steps:
- Selection. Determining whether the text contains a claim that can be objectively verified (opinions and predictions, for example, are excluded).
- Research. Each verifiable claim is compared against primary sources, public data, reliable studies, or consultations with experts.
- Evaluation. Based on this information, each ad is assigned a label: "false," "misleading," "true," or "not fact-checkable."
The analysts also reviewed the automated classification and excluded ads categorized as Health and Beauty but pertained to other topics.
All analyzed ads and their respective evaluations can be downloaded here.
Editing: Alexandre Aragão and Fernanda da Escóssia
