MDPI journal still publishing ‘cruel and unnecessary’ research despite extra checks, campaigners say

Janine McCarthy

New editorial policies at an MDPI title accused of publishing “sadistic, cruel, and unnecessary” animal studies are missing the mark, according to the Physicians Committee for Responsible Medicine (PCRM), a U.S-based advocacy group.

The group is waging a campaign against MDPI’s Nutrients, which it says is “publishing egregious animal experiments that could have been ethically conducted in humans.” The journal’s guidelines require the “replacement of animals by alternatives wherever possible,” as a PCRM guest post for Retraction Watch pointed out last year.

A former reviewer for the journal, and one of the more than 1,100 signatories of a recent PCRM boycott letter, said she resigned from the post after realizing Nutrients published research that was “sadistic, cruel, and unnecessary,” according to a press release from November.

Email correspondence made public here for the first time shows Nutrients continues to reject the group’s concerns. In one message from 2022, it told PCRM that 21 papers flagged as problematic “contained ethics statements that are in accordance with the journal policies.” 

After PCRM complained in December 2022 to the Committee for Publication Ethics (COPE), a nonprofit providing guidance to editors and publishers, an MDPI research integrity manager explained that “we are reliant on the decisions made by appropriate institutional ethics committees and institutional review boards in this matter, and we consider at this stage the investigation concluded.”

But he added that “as a result of this complaint, Nutrients has strengthened its processing procedures by implementing extra checks, facilitating increased editorial board participation, separated decision steps, and editorial board training to proactively identify these issues.”

These changes included:

  • Strengthened pre-screening check made by the editorial office, through a system integrated into our submission processing platform, to individually identify manuscripts involving animal research, and ensure relevant ethical approval and methodological information is provided as per our policy before further processing can take place.
  • Introduction of a mandatory academic editor pre-check decision before acceptance to peer-review for manuscripts involving animal research.
  • Introduction of a requirement for an academic editor with expertise in animal research to be invited to supervise peer-review on these manuscripts and make the final acceptance decision.

Training for the Journal editorial board members is an ongoing process. So far it has included conversations between trained in-house editorial staff and the editorial board about this issue, as well as constant reminders and sharing of information about the journals animal research policies and their responsibilities, as members of the editorial board in this regard. The journal has also placed increased emphasis on this within the information packet that all editorial board members receive. And finally, editorial staff have initiated discussion with senior editorial board members about the necessity for recruiting more members with specific expertise in this area to strengthen the current coverage for this subject.

COPE found no fault with how the journal handled PCRM’s concerns, adding:

We appreciate that this may not satisfy the presenter’s concerns regarding the specific articles, their design and research justification, but it is beyond the remit of the Facilitation and Integrity subcommittee to comment on the scholarly content of publications. 

Janine McCarthy, science policy program manager at PCRM, said the new editorial policies have fallen short.

“None of the checks that they implemented really take a look and say, does this actually meet Nutrients’ guidelines to use replacements [to animals] when available?” McCarthy told Retraction Watch. 

“They should be responsible for the types of papers that they publish, and they should be doing an additional check to make sure that the papers that they’re publishing in their journal actually adhere to their guidelines,” she said. “It’s not hard. It didn’t take us very long to find alternatives that were available for all these studies that they’re publishing.”

Nutrients, an open-access journal, charges authors 2,900 Swiss francs (about US$3,400) to get published. According to PCRM, the payments  come out to more than US$16 million annually. The group has found animal studies make up about a fifth of Nutrients’ publications, netting MDPI more than US$3 million in author fees.  

One such study that PCRM has flagged looked at saffron’s potential effect on depression. Here is how McCarthy described the research in a Retraction Watch guest post from March:

The manufacturer of a saffron-based nutrition supplement explored the spice’s purported mood-boosting properties. But rather than administering the supplement to volunteers and tracking their depressive symptoms with validated instruments, as other researchers have done, the manufacturer force-fed it to mice via gavage and dropped the animals in water tanks to conduct forced swim tests as a measure of their mood. 

“It seems to us that there is an incentive to just publish research no matter the quality,” said McCarthy, adding that the new policies appear to have had little effect on what appears in the journal. 

“We haven’t noticed any difference,” she said.

In a December editorial, Nutrients’ two editors-in-chief defended themselves against the criticism, writing:

.. we all agree that animal experimentation should never be the preferred method of testing.

Nor should it be regarded as a failsafe way of demonstrating drug safety and efficacy in and of itself. However, there may be instances where animal experimentation offers the only viable means of securing therapeutic benefits that will help alleviate forms of human suffering that are currently unaddressed.

We would like to call on all institutions that carry out such tests to do everything in their power to adopt the necessary measures and controls so as to obviate the need for animal experimentation in the first place. 

“The editors and the journal in general are trying to wash their hands clean, saying that they don’t participate in animal research as a journal,” McCarthy said. “And be that as it may, they still should be responsible for the types of papers and research that they publish.”

Giulia Stefenelli, chair of MDPI’s scientific board, reiterated that Nutrients had investigated the articles flagged by PCRM. 

“On our side, we consider this matter closed and we will not comment on this further,” she told Retraction Watch, speaking on behalf of MDPI’s management team. 

Stefenelli also listed the editorial changes Nutrients had put in place, adding: 

On top of this, the journal Nutrients is in the process of further strengthening the procedure requiring for [sic] authors to submit a ARRIVE checklist (ARRIVE Compliance Guidelines ( at submission stage, and for authors to justify the use of animals in the study within the submission cover letter, which will be reviewed by the Academic Editor during the pre-check phase.

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17 thoughts on “MDPI journal still publishing ‘cruel and unnecessary’ research despite extra checks, campaigners say”

  1. It seems there are serious concerns regarding mpdi publication which I tend to agree. However it is becoming very difficult for us, scientist of south America, to publish in Elsevier, Springer etc due to the scorching APC traditional publishers are charging us. This is why we have seen good research being channel through mpdi. It is time to rethink the publication model since pricing is becoming a burden even for scientist of developed countries.

    1. I sympathize with this issue, which is often used to explain how MDPI may satisfy a particular need, but institutions need to be educated that publishing in MDPI journals adds no more legitimacy to a paper than does publishing a preprint. If the institution is paying an APC (which I understand might be sometimes waived), that money is wasted and perpetuates their existence. There has to be a better solution.

  2. “However, there may be instances where animal experimentation offers the only viable means of securing therapeutic benefits that will help alleviate forms of human suffering that are currently unaddressed.”

    Using the saffron experiment as an example, the situation is even worse than noted. Yes, humans could have been used for the study, but also: there is lots of evidence that suggests that treatments like this in animal models do not translate well to humans (who presumably would be using saffron for themselves, not their depressed pet mice).

  3. Every single antidepressant that works in humans provokes longer swimming times in the forced swim test, which is where mice and rats swim about in warmish water for 3-5 minutes before giving up and floating, at which point they’re removed, dried on a warming plate and returned to their cage. It therefore seems that this is one of the few legitimate uses for the test and interviewing humans would be a far messier way of trying to infer changes to mood that could be solidly linked to the spice.
    It therefore seems that it’s the pressure group that’s problematic here. MDPI’s got 99 problems, but accepting this methodology in this case ain’t one of them.

    1. Jemma – Thanks much for adding science to this discussion! It’s invaluable to have an animal model to test drugs for use in humans.

    2. Can you also describe gavage as administered to mice and rats?

      I’m also curious about the “giving up and floating” – does this mean during the swim phase mice/rats are unable to grab hold of the sides of the tank? When the mice/rats “give up,” is this a cognitive recognition on their part that there is no escape from the tank, or is this a fatigue reaction, or….? What I’m asking is how the swim test is interpreted. How are we certain it means antidepressants are working on depression?

      1. Great questions. I’ve always wondered how a swim test correlates to mood in rats and mice. And, why would you not want to use humans to test this particular hypothesis? That’s better evidence because its real-world, particularly if there are no safety concerns for humans. Yes, it’s messy, but it’s also how things like this function in reality. Why do an animal test (unless there a safety/efficacy concerns) when it’s not needed?

  4. The MDPI journals are just for business they do not care about the quality of the presented research.

    I am a former reviewer in these journals and found terrible research have been accepted. Most of the reviewers do not care much about the quality of the research published in these journals

    1. On quality issues alone, I notified MDPI editors (November 2023) that I was no longer willing to review papers for them. Several papers that I reviewed were of such poor quality methodologically that “their publication would be an embarrassment to all stakeholders”. They were published nonetheless, with the other reviewers having offered feedback of such superficiality, suggesting they were unfamiliar with the methodological issues.

    2. I disagree with you. I submitted 19 manuscripts to two mdpi journals and only one was accepted and published.

      1. Sorry for misinterpreting mdpi archiving methodology. The total number of submissions was eight. Only one was accepted and published

  5. It should be noted that PCRM is a pro vegan organization, so take their criticisms of animal research with this in mind. Their objective is to end animal research. I am not necessarily against this endeavor; however, they are singling out Nutrients and MDPI when many other prestigious journals publish animal research that could be argued are better conducted in humans (e.g. nutrition investigations in cvd or cancer). Animal research is a reality of our world, while I agree that it is not the most ethical activity we do, it serves a greater good. The saffron example is an outlier compared to many animal studies published in Nutrients.

  6. Can the Retract Watch staff, or perhaps the Center For Scientific Integrity Board of Directors, explain how the mission of “Tracking retractions as a window into the scientific process” apparently includes being a mouthpiece for PETA and similar organizations?

    1. Did you need to learn to read ?
      “The mission of the Center for Scientific Integrity, the parent organization of Retraction Watch, is to promote transparency and integrity in science and scientific publishing, and to disseminate best practices and increase efficiency in science.”
      Integrity, sound methodologies and ethics are pilar of best practices in science.

    2. The ethical conduct of research is of fundamental importance. In this case, PETA is acting as a mouthpiece for the animals themselves who, although they can suffer, cannot voice their ethical concerns.

      Do you have a problem with the ethical principles governing the use of animals in research? If so, please explain. You may view them here:

  7. I’m not in favour of MDPI, but I would say many Elsevier journals (especially new joutnals) are publishing rubish, and some others (old journals) are shifting towards price model (APC much higher than MDPI)… So I would equaly blame all big giants, inclusing Elsevier!

  8. My research interest has been to explore alternative methodologies to climate change science, such as using thermodynamics instead of the radiative forcing of the greenhouse gas effect. I assure you from my lengthy personal experience that traditional journals of climate and publishers do not consider alternatives to the existing climate radiative forcing methodology. Here is the proof and what a traditional journal editorial board would say and do:
    Instead, MDPI has provided a platform to consider and publish climate change related papers based on their scientific content and merit and not based on the politics of the climate science. For this reason MDPI should be given some respect in my opinion.

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