Short answer: An indexed journal is one that a bibliographic database has evaluated and agreed to include, so its articles can be found by anyone searching that database. In medicine the indexes that matter most are MEDLINE/PubMed, Embase, Scopus and Web of Science. Indexing is granted to journals, not individual papers, and once a journal is indexed, its new articles typically appear within days to weeks of publication.
What "indexed" actually means
A database such as Embase does not host journals. It keeps a record of every article from the journals it covers: title, authors, abstract, keywords and subject terms. When you search the database, you are searching those records.
The curated databases decide which journals to cover. They look at the editorial board, peer review process, publication ethics, regularity of publishing and the scientific quality of the content. That selection is why indexing carries weight: a journal in Embase or MEDLINE has passed an external review of its standards.
Many institutions, regulators and promotion boards specify which indexes they accept. In India, for example, medical faculty promotion rules have referred to journals indexed in databases such as Embase, MEDLINE/PubMed, Scopus and Web of Science. Always check the current rules that apply to you.
The main indexes compared
| Index | Run by | Coverage | Free to search? |
|---|---|---|---|
| MEDLINE / PubMed | US National Library of Medicine | Biomedicine and life sciences; MEDLINE records indexed with MeSH terms | Yes |
| Embase | Elsevier | Biomedicine and pharmacology; includes MEDLINE plus thousands of extra journals, strong on drugs, devices and European and Asian research; indexed with Emtree | No, institutional subscription |
| Scopus | Elsevier | Multidisciplinary abstracts and citations | No (source list is free) |
| Web of Science | Clarivate | Multidisciplinary, selective; home of the Journal Impact Factor | No |
| DOAJ | Independent non-profit | Quality-screened open access journals | Yes |
| Google Scholar | Automated web crawl, not curated | Yes |
Embase vs PubMed: which matters more?
They overlap but are not the same. Embase contains virtually all MEDLINE content and adds journals that MEDLINE does not cover, which is why systematic review guidelines recommend searching both. For pharmacology, drug safety and clinical research from outside North America, Embase coverage is often the more relevant one. For a deeper look at the cost side, see Embase pricing explained.
How long does indexing take?
There are two very different timelines, and mixing them up causes a lot of confusion.
1. A new article in an already-indexed journal
This is the timeline most authors care about. The journal is already covered, so the only question is how quickly the database adds new records.
- PubMed: usually within days to a few weeks after publication, once the publisher submits the citation data or deposits the article in PubMed Central. Full MEDLINE indexing with MeSH terms follows, now largely automated.
- Embase: typically within a few weeks of online publication, depending on how the journal's content is delivered to Elsevier.
- Scopus and Web of Science: generally a few weeks, varying by journal.
2. A journal applying to be indexed
A journal must apply to each database and be evaluated. This usually requires a track record of regular publishing and typically takes many months, sometimes longer. If rejected, a journal often has to wait before reapplying. This is why you should only trust indexing that is already in place, not "indexing in process".
Important: authors cannot get a single article indexed in PubMed, Embase or Scopus. If a journal is not indexed, its articles will not appear, whatever fee is paid. Be cautious of anyone offering "PubMed indexing" for an individual paper.
How to check a journal's indexing yourself
- Embase: search the ISSN in Elsevier's Embase journal title list. Our step-by-step Embase check explains how.
- MEDLINE/PubMed: search the NLM Catalog and look at "Current Indexing Status".
- Scopus: search the free Scopus Sources list.
- Web of Science: use Clarivate's Master Journal List.
Always search by ISSN, and confirm the ISSN on the ISSN Portal, because cloned journals often copy real titles.
Frequently asked questions
What does it mean when a journal is indexed?
It means a bibliographic database, such as Embase, MEDLINE, Scopus or Web of Science, has evaluated the journal and agreed to include its articles. Researchers searching that database can then find the journal's papers. Curated databases apply selection criteria, so indexing is a signal of quality and visibility.
How long does PubMed indexing take?
For a journal that is already indexed in MEDLINE or deposits in PubMed Central, new articles usually appear in PubMed within days to a few weeks of publication, once the publisher sends the data. For a journal that is not yet indexed, the journal itself must apply to the National Library of Medicine, and evaluation typically takes many months. An individual author cannot get a single article indexed in PubMed.
How long does Embase indexing take?
For a journal already covered by Embase, new articles are usually added within a few weeks of publication, depending on how the journal delivers its content to Elsevier. A journal applying for coverage goes through Elsevier's evaluation, which takes considerably longer.
Is Google Scholar an indexed database?
Google Scholar indexes papers automatically by crawling the web. It is useful for discovery, but it does not evaluate journal quality, so appearing in Google Scholar is not the same as being indexed in a curated database such as Embase or MEDLINE.
Are PubMed and MEDLINE the same?
No. MEDLINE is the curated, MeSH-indexed core of PubMed. PubMed also includes articles deposited in PubMed Central and some other content. A journal can have articles in PubMed without being indexed in MEDLINE.
Looking for an Embase-indexed journal for your manuscript? Browse our journals list or read about our Embase indexed publication service.