Is Molecules (MDPI) Predatory? A Practical Verdict

This page was created from official-source facts and Manusights internal analysis of chemistry manuscripts considering MDPI journals. Sources used include the Molecules journal page, MDPI indexing information, DOAJ, Clarivate JCR, SCImago, JUFO's public reclassification note, and published reporting on special-issue behavior. We did not treat publisher reputation as a single yes/no signal. We separated indexing legitimacy, peer-review structure, special-issue risk, institutional credit, and manuscript-fit risk because authors searching "is Molecules predatory" usually need a submission decision, not a slogan.

Our review data also separates this page from a generic MDPI verdict. A manuscript can be a reasonable fit for Molecules while a specific special issue, guest editor, or career context makes the submission a poor move.

MDPI was on Beall's list from 2014 to 2015 before a successful appeal reviewed by Beall's own appeals board. The Open Access Scholarly Publishers Association (OASPA) also investigated and confirmed MDPI met its membership criteria. When Beall's list was revived by other maintainers, they explicitly excluded MDPI. But the original listing lives on in searches.

MDPI also sends a high volume of solicitation emails - invitations to submit, to guest-edit special issues, to join editorial boards - that feel similar to predatory publisher tactics, even though it is aggressive marketing rather than fraud. Beall himself called these "warehouse journals" filled with "lightly-reviewed articles."

Finland downgraded 193 MDPI journals to Level 0 in December 2024. Norway has been critical of MDPI broadly. Clarivate delisted two other MDPI journals in 2023, though Molecules was not affected. In 2023, Predatory Reports added all MDPI journals to its predatory list - a controversial decision. These publisher-level actions generate the "is it predatory?" searches.

Molecules was founded in 1996, making it one of the earliest open-access chemistry journals and one of MDPI's longest-running titles. Its editorial board exceeds 1,700 members, all working chemistry researchers at recognized institutions.

It is indexed in SCIE (Q2 in Chemistry, Multidisciplinary at rank 75/239; Q2 in Biochemistry and Molecular Biology at rank 82/319), Scopus (Q1 in Analytical Chemistry, Organic Chemistry, Pharmaceutical Science, and Physical and Theoretical Chemistry), PubMed, and DOAJ. Its Impact Factor is 4.6, CiteScore is 5.9, SJR is 0.865, and h-index is 261.

Annual output is approximately 4,828 articles, with over 60,000 total articles across its history. The APC is CHF 2,700. Average submission-to-publication time is 38 days, with a median of 34 days. Revised manuscripts are reviewed within 3 days.

These numbers put Molecules firmly in the mid-tier of chemistry journals - not Nature Chemistry (IF 19.2) or JACS (IF 14.4), but a credible venue that most chemistry departments recognize.

A predatory journal does not maintain SCIE indexing for nearly three decades, accumulate an h-index of 261, or build a 1,700-member editorial board of working chemists. Molecules passes every standard test for journal legitimacy.

The risk is the special issue model and review speed.

In 2022, 88% of all MDPI articles appeared in special issues rather than regular issues (since reduced to 55%). Guest editors running those issues become the primary quality gatekeepers, and not all are equally rigorous. A Science investigation found that MDPI accounted for 87% of special issues where guest editors contributed more than a third of the papers themselves. Thirteen percent of MDPI special issues exceeded a threshold where more than a third of papers were co-authored by the guest editor. For Molecules specifically, the quality of any given paper depends heavily on which special issue it appeared in and who was overseeing it.

The 38-day average submission-to-publication time is roughly five times faster than traditional chemistry journals where 2-4 months for first decision and 6+ months for total publication is normal. Reviewers get 7-10 days. Whether meaningful chemistry peer review - evaluating experimental procedures, spectral data, synthetic methodology - can consistently happen in that window is the core question.

The 2018 mass resignation at MDPI's Nutrients journal, where 10 senior editors left over alleged pressure to accept mediocre manuscripts, illustrates a structural tension across MDPI between editorial selectivity and business growth. That incident did not involve Molecules directly, but it describes a publisher-wide dynamic.

The better question is whether Molecules is the right journal for this particular paper. If your chemistry research is sound, you want open-access publication with PubMed indexing, and a mid-tier IF works for your career, Molecules is a legitimate option with nearly 30 years of track record.

If your paper has enough novelty for Organic Letters, Chemical Communications, JACS, or Angewandte Chemie, those venues carry a stronger selectivity signal. If your institution uses Finland's JUFO system, publication in Molecules earns minimal credit. If you want your work associated with a society publisher (ACS, RSC, Wiley-VCH), those carry different reputational weight.

If submitting to a special issue, vet the guest editor's record and check whether they have published excessively in their own issues.

If you are considering a Molecules special issue, do some homework first. Check the guest editor's h-index and publication record - are they active researchers in the special issue's topic? Look at other papers already published in the issue and assess whether quality is consistent with what you expect from an IF 4.6 journal. Check whether the guest editor has published their own papers in the issue - one paper is common, three or four is a red flag. Compare the special issue's topic to the guest editor's expertise. A mismatch suggests the editor may have been recruited for volume rather than knowledge.

For regular issues, the journal's main editorial pipeline provides more consistent oversight.

In our pre-submission review work with chemistry manuscripts considering Molecules, three specific failure patterns recur.

Authors ask the wrong legitimacy question. We often see authors treating "not predatory" as equivalent to "good target." Those are different decisions. Molecules passes the legitimacy screen, but the stronger question is whether the paper benefits from a broad open-access chemistry venue or would carry more career value in an ACS, RSC, Wiley-VCH, or society journal.

Special-issue fit is accepted too quickly. Manusights internal analysis shows the highest submission risk when authors respond to an invitation without checking the guest editor's publication record, prior special-issue papers, and topic match. The issue may be legitimate, but the editorial quality gate can vary more than in a regular issue.

Institutional credit is checked too late. We see this most often with authors in systems where journal lists affect promotion, funding, or doctoral requirements. Finland's Level 0 treatment is not a universal verdict, but it matters if your institution uses similar lists or views MDPI special issues skeptically.