How to Use NCCIH, MedlinePlus, LiverTox and LactMed
How to look up a herb or supplement in NCCIH and MedlinePlus, what LiverTox and LactMed are for, and the limits of each, including what we could not open.
Content last updated . This page has not been medically reviewed.
Urgent first: if someone may have swallowed something harmful, call Poison Help at 1-800-222-1222 (US) or 911 if they collapse, have a seizure or struggle to breathe. Do not look it up first.
These four sources answer different questions. This page says which to use for what. We could read NCCIH and MedlinePlus on 2026-10-23. We could not open LiverTox or LactMed themselves, so our description of them comes from published papers, not from their pages.
Which source answers which question
| Your question | Source to try | What the sources say it is | Strength of what we can say |
|---|---|---|---|
| "What is this herb, and is it safe?" | NCCIH Herbs at a Glance | Brief fact sheets with basic information on specific herbs [1] | Read directly |
| "Could this clash with my medicine?" | NCCIH interaction guide, then MedlinePlus | Supplements may raise or lower a medicine's effects, or interact harmfully [2] | Read directly |
| "Is this safe while breastfeeding?" | LactMed | A database on medicines used during lactation, with drug levels in breast milk [3] | Described by a 2007 paper only |
| "Could this harm my liver?" | LiverTox | A database that compiles cases of drug-induced liver injury [4] | Described by a 2021 critique only |
| "What do the studies say?" | PubMed | Search of biomedical literature; it does not include full-text articles [5] | Read directly |
Using NCCIH
Start with the herb's fact sheet, then read the interaction guide. NCCIH says taking medicines and supplements together may increase or decrease the medicine's effects, or interact in harmful ways. [2] It advises talking with your health care providers about all supplements and medicines you take. [2] It also notes that many supplements have not been tested in pregnant women, nursing mothers or children, and that some can carry risks around surgery. [6]
Using MedlinePlus
MedlinePlus is a National Library of Medicine service for patients and families. [7] Its Herbs and Supplements page invites you to browse for effectiveness, usual dosage and drug interactions. [8] Be aware that the page says information from the Natural Medicines Comprehensive Database became unavailable on July 29, 2025. [8] Its Dietary Supplements topic page says supplements do not have to go through the testing that drugs do. [9] It also says to check with your provider about supplements before any type of surgery. [9] See supplements before surgery.
Using LactMed
A 2007 paper called LactMed a peer-reviewed database from the National Library of Medicine, with data on levels of medicines in breast milk and infant blood. [3] We could not open LactMed, so we cannot say how many herbs or supplements it covers today. Proper evidence not found on this site for its current coverage; we searched the database page and PubMed. For now, see pregnancy and breastfeeding and ask a pharmacist.
Using LiverTox
A 2014 paper by a US National Institute of Diabetes and Digestive and Kidney Diseases author describes LiverTox as an online information resource and a site for case report submission. [10] A 2021 paper describes it as compiling idiosyncratic drug-induced liver injury cases, and reports concerns that some cases were of insufficient quality. [4] Treat an entry as one input, and bring liver symptoms to a clinician. See liver safety.
Limits that apply to all four
- None of them replaces your pharmacist or prescriber, who know your medicines.
- A missing entry is not proof of safety.
- Do not use any of them to decide to stop or change a prescribed medicine. Ask the prescriber or pharmacist.
Frequently asked questions
Is NCCIH advice or a medical opinion about me?
No. Its pages are general public information. [1] Ask a clinician about your situation.
Where do I look for a herb and medicine interaction?
Start with the NCCIH interaction guide. [2] Then ask your pharmacist. See how to check an interaction safely.
Why can't this site quote LiverTox or LactMed directly?
A browser check blocked our system from both on 2026-10-23, and we do not get around such checks.
Does MedlinePlus still have the herb database it once had?
It states that one commercial database's content became unavailable as of July 29, 2025. [8] Entries linked from NCCIH and ODS are listed on the same page. [8]
Can PubMed tell me if a supplement is safe?
It helps you find study abstracts, but it does not include full articles. [5] Study results depend on the plant part, product, people and outcome. See how to read the research library.
References
- NCCIH (NIH, US), Herbs at a Glance. Read 2026-10-23.
- NCCIH (NIH, US), Know the Science: How Medications and Supplements Can Interact, Introduction. Read 2026-10-23.
- Tomasulo P. LactMed, new NLM database on drugs and lactation. Med Ref Serv Q. 2007. PubMed abstract 17210549. Read 2026-10-23.
- Teschke R, Danan G. The LiverTox Paradox. Diagnostics (Basel). 2021. PubMed abstract 34679453. Read 2026-10-23.
- National Library of Medicine (US), About PubMed. Read 2026-10-23.
- NCCIH (NIH, US), Using Dietary Supplements Wisely. Read 2026-10-23.
- MedlinePlus (National Library of Medicine, US), About MedlinePlus. Read 2026-10-23.
- MedlinePlus (National Library of Medicine, US), Herbs and Supplements. Read 2026-10-23.
- MedlinePlus (National Library of Medicine, US), Dietary Supplements. Read 2026-10-23.
- Serrano J. LiverTox: An online information resource and a site for case report submission on drug-induced liver injury. Clin Liver Dis. 2014. PubMed record 30992914. Read 2026-10-23.