International Journal of Molecular Sciences Formatting Requirements: Complete Author Guide

IJMS keeps its abstract format simple and consistent across article types.

• Word limit: 200 words maximum
• Structure: Unstructured (single paragraph)
• Citations: Not allowed
• Abbreviations: Define on first use within the abstract

The 200-word abstract should state the research question, describe the approach, present the main results with key data points, and briefly address significance. Don't start with generic background. Get to the point quickly.

MDPI journals display the abstract prominently on the article landing page, and it's the primary text used by indexing services. Make every word count.

Keywords: IJMS requires 3-8 keywords, listed below the abstract. Choose terms that reflect the specific content of your paper rather than broad field descriptors. Keywords should not duplicate words from the title. MDPI uses these for internal categorization and to match papers with editors and reviewers.

A detail specific to MDPI journals: keywords are displayed on the article page and used in the journal's search function. They're more visible than at Elsevier or Wiley journals, so treat them as a discovery tool, not just a formality.

IJMS doesn't impose a strict figure count for research articles. The number of figures should be appropriate to the content. That said, most published research articles include 4-8 figures and 1-3 tables.

Figure specifications:

MDPI-specific figure rules:

MDPI journals have a distinctive approach to figure placement. Figures should be inserted directly in the text at the point where they're first cited, not grouped at the end. This is different from most traditional journals and is part of MDPI's formatting template.

Each figure needs:

• A figure caption below the figure
• Caption starts with "Figure X." in bold, followed by the description
• Multi-panel figures labeled (a), (b), (c), etc.
• All panels explained in the caption

Table formatting:

• Tables are placed in-text, like figures
• Every column must have a header
• Table title goes above the table as "Table X." in bold
• Use the MDPI table style (minimal horizontal rules, no vertical rules)
• Footnotes below the table using superscript numbers

Graphical abstract: Optional for IJMS. If included, it should be a single image that visually summarizes the study. MDPI doesn't enforce specific dimensions, but recommends a landscape orientation at 300 dpi minimum.

IJMS uses the MDPI reference style, which has several distinctive features that set it apart from Elsevier and Wiley formats.

In-text citations: Square brackets with numbers, e.g., [1], [2,3], [4-7]. Numbers assigned by order of first appearance.

Reference list format:

1. Author, A.B.; Author, C.D. Title of Article. Full Journal Name Year, Volume, Pages.

Key formatting details that make MDPI's style distinctive:

• Author names: Last name, then initials with periods (Smith, J.K.)
• Semicolons between authors (not commas)
• Journal titles are spelled out in full (not abbreviated). This is the biggest difference from other styles.
• Volume in bold, followed by page numbers
• DOIs are required for all references that have them
• URLs included for web-based references with access dates
• Maximum 6 authors listed, then "et al." for papers with 7+ authors

The full journal title requirement catches many authors off guard. "Chem. Eng. J." won't work; you need "Chemical Engineering Journal." This applies to every journal in your reference list. If you're using a citation manager, make sure it's configured for the MDPI style, not a generic numbered style.

MDPI provides reference formatting templates for EndNote, Zotero, and Mendeley on the MDPI author instructions page. Use them. The full journal title requirement alone makes manual formatting impractical for papers with 30+ references.

IJMS uses MDPI's standard supplementary material system. Supplementary files are hosted on the MDPI website alongside the article and are freely accessible.

What goes in supplementary material:

• Extended methods and protocols
• Additional figures and tables
• Raw data files (Excel, CSV)
• Video files
• Code and scripts
• Questionnaires and survey instruments

MDPI supplementary formatting:

• Supplementary items are numbered sequentially (Figure S1, Table S1)
• Each item must have a caption
• Submit supplementary material as a single PDF for text-based content
• Data files and videos submitted separately
• Every supplementary item must be cited in the main text

MDPI has a strong emphasis on data transparency. IJMS encourages authors to make all underlying data available, either as supplementary files or through public repositories. The journal supports MDPI's Data Availability Statement policy, which requires specifying where data can be accessed.

Data Availability Statement: Mandatory for all IJMS articles. Placed at the end of the manuscript before Acknowledgments. You must select one of MDPI's standard templates:

• Data available in the article or supplementary material
• Data available on request from the corresponding author
• Data deposited in a publicly accessible repository
• No new data were created or analyzed

IJMS uses MDPI's Susy (Submission System) for online submission.

Cover letter: Recommended but not always strictly required. If you include one:

• State the article type
• Describe the novelty briefly
• Confirm the work is original and not under review elsewhere
• Suggest potential reviewers (optional but helpful)

Required submission components:

• Manuscript in MDPI template (Word or LaTeX)
• All figure files (embedded in manuscript and/or separate high-resolution files)
• Supplementary material files
• Data Availability Statement (within the manuscript)
• Author Contributions statement (within the manuscript)
• Conflicts of Interest statement (within the manuscript)
• Funding statement (within the manuscript)

Author Contributions: IJMS requires a structured author contributions statement using CRediT-style categories. This is placed at the end of the manuscript, after the Conclusions and before the References.

Institutional Review Board statement: For studies involving human subjects, include the ethics approval information. For animal studies, include IACUC or equivalent approval. These are placed as formal statements at the end of the manuscript.

These are the formatting details that regular IJMS authors know:

The MDPI template is mandatory from day one. Don't submit a generic Word document thinking you'll format it later. The editorial office will return it immediately. Download and use the template before you start writing.

Section numbering is built into the template. MDPI's template auto-numbers sections. Don't add manual numbering. The standard structure is: 1. Introduction, 2. Results, 3. Discussion, 4. Materials and Methods, 5. Conclusions. Note that MDPI places Materials and Methods after Discussion, not before Results.

Materials and Methods comes after Discussion. This is the opposite of most traditional journals. MDPI's standard section order is Introduction, Results, Discussion, Materials and Methods, Conclusions. If you're used to writing IMRaD (Introduction, Methods, Results, Discussion), you'll need to restructure.

In-text figure and table placement. Figures and tables go directly in the text at their first citation, not at the end of the manuscript. This is a distinctive MDPI requirement.

No line numbers for submission. Unlike Elsevier journals, MDPI's system adds reference identifiers during review. You don't need to add line numbers to your submitted manuscript.

APC-based publishing model. IJMS is fully open access with an article processing charge. The APC covers all publication costs including color figures. Be aware of this cost structure before submitting.

Special Issue submissions. IJMS publishes many Special Issues. If submitting to a Special Issue, select the correct one during submission. Special Issue papers go through the same peer review process as regular submissions.

Even regular IJMS authors miss these:

1. Full journal titles in references. This is the number one formatting error. MDPI requires complete, unabbreviated journal titles. Every single reference. No exceptions.

1. Section order. Materials and Methods after Discussion, not before Results. Authors who submit in traditional IMRaD order get their manuscripts returned.

1. Template usage. The manuscript must use the MDPI template. A well-formatted manuscript that doesn't use the template will be sent back.

1. Data Availability Statement placement. It goes at the end of the manuscript, after the main text and before Acknowledgments. Don't put it in the supplementary material.

1. Author Contributions format. Use the structured format: "Conceptualization, A.B. and C.D.; methodology, A.B.; investigation, C.D.; writing, A.B." etc.

In our pre-submission review work with manuscripts targeting International Journal of Molecular Sciences, four patterns generate the most consistent desk-rejection outcomes.

Mandatory MDPI template not used. IJMS requires all submissions to use the current MDPI Word or LaTeX template. Manuscripts formatted outside the MDPI template are returned before peer review. The mdpi LaTeX document class is required for LaTeX submissions. MDPI updates templates; authors should download the current version from the IJMS instructions page rather than reusing templates from previous submissions.

Abstract exceeds 200 words or contains citations, abbreviations, or equations. MDPI enforces a strict 200-word maximum abstract for IJMS. The abstract must be unstructured, without literature citations, undefined abbreviations, or mathematical formulas. A common error is citing prior work to contextualize the study in the opening abstract sentence, which is standard in many non-MDPI journals but explicitly prohibited here. Exceeding the word limit triggers a correction request at submission processing.

ORCID iD missing for corresponding author. IJMS requires the corresponding author to provide their ORCID iD at submission. This is enforced at the level of the MDPI submission system. Authors who have not registered for ORCID must do so before submitting. Co-author ORCID iDs are encouraged but optional. Submissions without the corresponding author's ORCID cannot progress until it is provided.

Full journal names not used in the reference list. IJMS uses MDPI reference style, which requires full, unabbreviated journal names. Authors from chemistry, biology, or medicine typically use abbreviated names from reference managers configured for other publishers (ACS, RSC, ICMJE). The MDPI format requires "International Journal of Molecular Sciences" in citations, not "Int. J. Mol. Sci." Manuscripts with abbreviated reference lists are returned for correction before review.

A International Journal of Molecular Sciences formatting and readiness check evaluates manuscript structure, MDPI template compliance, abstract length, and reference format against these desk-rejection patterns before you submit.