Is https://www.ncbi.nlm.nih.gov/books/NBK21535 blocked in mainland China?

Can you open https://www.ncbi.nlm.nih.gov/books/NBK21535 from mainland China?

Yes.

No recent testsVerdict from 2026-07-21 · 3 mo ago

As of the last test on 2026-07-21 — 3 mo ago — it was reachable in mainland China. We haven't tested it since, so this may have changed.

2017first tested

3 mo agolast tested

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Other tested URLs on nih.gov

Mixed4 blocked23 disrupted16 accessible4 no verdictAll 47 tested URLs on nih.gov →

Blocking varies across nih.gov: 4 blocked vs 16 accessible among tested hosts.

Each verdict covers the last 90 days of tests, as on that URL's own page.

Frequently asked questions

Is https://www.ncbi.nlm.nih.gov/books/NBK21535 blocked in mainland China right now?

We haven't tested https://www.ncbi.nlm.nih.gov/books/NBK21535 in the last 90 days. As of the last test on 2026-07-21 (3 mo ago), it was reachable in mainland China. Use the Test now button on this page for a fresh measurement.

https://www.ncbi.nlm.nih.gov/books/NBK21535 · JSON