Clinical reference list — top germ killing herbs against the 3 Bs, pregnancy risks, mechanisms, and numbered scientific references
Herbal products can affect pregnancy through uterine stimulation, hormonal activity, embryo-fetal toxicity, maternal organ toxicity, bleeding risk, or interactions with prescribed medications.
However, the evidence varies substantially. Some herbs have documented reproductive toxicity, while others are discouraged primarily because reliable human pregnancy safety data are lacking.
For clinical accuracy, I distinguish three categories:
- AVOID: Known or plausible serious pregnancy risks, including reproductive toxicity, uterotonic activity, or maternal toxicity.
- GENERALLY AVOID MEDICINAL DOSES: Concerning pharmacology, animal findings, or insufficient safety evidence.
- USE ONLY WITH CLINICAL SUPERVISION: Potential interactions or specific risks, rather than established fetal harm.
These classifications concern concentrated extracts, capsules, essential oils taken internally, medicinal teas, and therapeutic doses. Ordinary culinary quantities are often a different exposure and should not automatically be considered dangerous.
Importantly, none of the listed herbs should be used to induce menstruation or abortion without appropriate medical care. For an actual pregnancy exposure, the exact species, dose, formulation, route, and gestational age matter.
Master table: 50 herbs to avoid or restrict in pregnancy
Numbered citations in the final column correspond to the full reference list below. Several reviews cover multiple herbs; these are shared sources, not 50 separate human pregnancy trials.
Group A. Higher-concern herbs — avoid during pregnancy
| # | Herb (scientific name) | Main reason for concern | Ref. |
|---|---|---|---|
| 1 | Pennyroyal (Mentha pulegium) | Pulegone hepatotoxicity; potentially fatal poisoning; historical abortifacient use | 1, 3, 5 |
| 2 | Blue cohosh (Caulophyllum thalictroides) | Uterotonic activity; reported severe neonatal cardiovascular and neurological toxicity | 1, 6 |
| 3 | Black cohosh (Actaea racemosa) | Possible uterine effects; inadequate pregnancy safety evidence | 1, 6 |
| 4 | Goldenseal (Hydrastis canadensis) | Berberine exposure and potential neonatal bilirubin toxicity concerns | 1, 3 |
| 5 | Rue (Ruta graveolens) | Reproductive toxicity and severe maternal toxicity | 3, 5 |
| 6 | Tansy (Tanacetum vulgare) | Thujone-containing preparations; neurotoxicity and possible uterine effects | 3, 5 |
| 7 | Wormwood (Artemisia absinthium) | Thujone neurotoxicity; insufficient reproductive safety data | 3, 5 |
| 8 | Mugwort (Artemisia vulgaris) | Traditional uterine stimulant; pregnancy safety concerns | 1, 5 |
| 9 | Dong quai (Angelica sinensis) | Possible uterotonic effects; anticoagulant interactions | 3, 5 |
| 10 | Comfrey (Symphytum officinale) | Hepatotoxic pyrrolizidine alkaloids; potential fetal exposure | 3, 5 |
| 11 | Coltsfoot (Tussilago farfara) | Potential pyrrolizidine alkaloid hepatotoxicity | 5 |
| 12 | Aristolochia (Aristolochia spp.) | Aristolochic acid nephrotoxicity and carcinogenicity | 3 |
| 13 | Ephedra / ma huang (Ephedra sinica) | Sympathomimetic toxicity; hypertension, arrhythmias, maternal cardiovascular risk | 5 |
| 14 | Pokeweed (Phytolacca americana) | Toxic saponins and other constituents; serious poisoning risk | 5 |
| 15 | Bloodroot (Sanguinaria canadensis) | Toxic isoquinoline alkaloids; inadequate reproductive safety | 5 |
| 16 | Mayapple (Podophyllum peltatum) | Podophyllotoxin-related cytotoxicity and reproductive toxicity | 5 |
| 17 | Autumn crocus (Colchicum autumnale) | Colchicine-containing poisonous plant; potentially severe maternal toxicity | 5 |
| 18 | Lily of the valley (Convallaria majalis) | Cardiac glycosides; potentially fatal dysrhythmias | 5 |
| 19 | Mistletoe (Viscum album) | Toxic constituents and inadequate reproductive safety evidence | 5 |
| 20 | Thuja / arborvitae (Thuja occidentalis) | Thujone-containing oil; neurotoxicity and possible uterine effects | 5 |
For Group A, evidence ranges from documented human poisoning to preclinical toxicity and longstanding contraindications. Not every herb has demonstrated human teratogenicity.
Group B. Generally avoid medicinal doses — reproductive or pharmacological concerns
| # | Herb (scientific name) | Main reason for concern | Ref. |
|---|---|---|---|
| 21 | Feverfew (Tanacetum parthenium) | Possible uterine stimulation; insufficient fetal safety data | 1, 3 |
| 22 | Yarrow (Achillea millefolium) | Possible uterine effects; limited pregnancy studies | 5 |
| 23 | Motherwort (Leonurus cardiaca) | Traditionally used for uterine activity; limited human safety data | 5 |
| 24 | Shepherd’s purse (Capsella bursa-pastoris) | Potential uterine stimulation | 5 |
| 25 | Cotton root bark (Gossypium spp.) | Traditional uterotonic use; reproductive toxicity concerns | 5 |
| 26 | Fenugreek (Trigonella foenum-graecum) | Animal reproductive findings; possible uterine stimulation and glucose effects | 3, 4 |
| 27 | Licorice root (Glycyrrhiza glabra) | Glycyrrhizin-related hormonal and blood pressure effects; adverse pregnancy associations | 1, 2, 4 |
| 28 | Barberry (Berberis vulgaris) | Berberine exposure; potential neonatal bilirubin toxicity concern | 3, 5 |
| 29 | Oregon grape (Mahonia aquifolium) | Berberine-containing preparation; insufficient pregnancy safety | 3, 5 |
| 30 | Aloe latex (Aloe vera, latex portion) | Anthraquinone stimulant laxative; cramping and electrolyte effects | 3, 4 |
| 31 | Cascara sagrada (Frangula purshiana) | Stimulant laxative; prolonged use may cause electrolyte disturbances | 5 |
| 32 | Sassafras (Sassafras albidum) | Safrole toxicity and carcinogenicity concerns | 5 |
| 33 | Calamus (Acorus calamus) | Beta-asarone toxicity and carcinogenicity concerns | 5 |
| 34 | Borage (Borago officinalis) | Pyrrolizidine alkaloid contamination in some preparations; insufficient pregnancy safety | 3 |
| 35 | Wild ginger (Asarum spp.) | Some species/products contain nephrotoxic aristolochic acids | 5 |
| 36 | Ginkgo (Ginkgo biloba) | Potential platelet effects and bleeding concerns; limited pregnancy safety | 3, 4 |
| 37 | Chasteberry (Vitex agnus-castus) | Dopaminergic and reproductive endocrine activity; insufficient pregnancy safety | 3 |
| 38 | Saw palmetto (Serenoa repens) | Antiandrogenic activity; theoretical fetal endocrine effects | 5 |
| 39 | Roman chamomile (Chamaemelum nobile) | Possible uterine effects; limited safety evidence at medicinal doses | 5 |
| 40 | Juniper berries (Juniperus communis) | Traditional uterine stimulant; renal irritation and pregnancy safety concerns with concentrated preparations | 5 |
Group C. Avoid unsupervised medicinal use — evidence is limited or context-dependent
| # | Herb (scientific name) | Main reason for concern | Ref. |
|---|---|---|---|
| 41 | Sage (Salvia officinalis) | Concentrated oil contains thujone; culinary amounts differ | 3, 5 |
| 42 | Thyme (Thymus vulgaris) | Concentrated essential oil and medicinal doses inadequately studied; food amounts generally acceptable | 3 |
| 43 | Parsley seed/oil (Petroselinum crispum) | Concentrated apiol/myristicin exposure; toxic and possible uterine effects | 5 |
| 44 | Nutmeg oil (Myristica fragrans) | High-dose myristicin toxicity; culinary amounts generally acceptable | 5 |
| 45 | Kava (Piper methysticum) | Potential liver toxicity, sedation and inadequate fetal safety data | 5 |
| 46 | Yohimbe (Pausinystalia johimbe) | Yohimbine-associated hypertension, tachycardia and CNS effects | 5 |
| 47 | St. John’s wort (Hypericum perforatum) | Important drug interactions; limited pregnancy outcome evidence | 4, 5 |
| 48 | Valerian (Valeriana officinalis) | CNS effects; insufficient human pregnancy safety evidence | 3, 4 |
| 49 | Ginseng (Panax ginseng) | Possible hormonal and metabolic effects; limited reproductive safety evidence | 4, 5 |
| 50 | Passionflower (Passiflora incarnata) | Possible uterine effects; limited human pregnancy safety evidence | 5 |
Clinical distinction: Groups B and C are not evidence that all listed herbs cause miscarriage or birth defects. For several, the appropriate conclusion is that medicinal exposure is not sufficiently established as safe.
The NIH Office of Dietary Supplements and systematic reviews support particular caution with pregnancy use of concentrated botanical products.
Health Professional Fact Sheet+2
Full scientific references and endnotes
The following six principal sources support the 50-item screening table. These include systematic reviews, clinical summaries, toxicology information, and institutional safety guidance. They do not provide equal-strength evidence for every herb.
1. National Institutes of Health, Office of Dietary Supplements. Dietary Supplements and Life Stages: Pregnancy—Health Professional Fact Sheet. Bethesda, MD: National Institutes of Health. Section: Other Botanicals. Discusses goldenseal, mugwort, pennyroyal, feverfew, licorice, fenugreek, cohosh, and other botanicals with potential pregnancy risks.Full NIH reference (opens in new tab)
2. Muñoz Balbontín Y, Stewart D, Shetty A, Fitton CA, McLay JS. Herbal medicinal product use during pregnancy and the postnatal period: a systematic review. Obstetrics & Gynecology. 2019;133(5):920–932. doi:10.1097/AOG.0000000000003217.
This systematic review included 74 studies and more than one million women. It reported associations involving heavy licorice exposure, raspberry leaf, and other herbal preparations. Observational associations do not independently establish causation.PubMed — Full study (opens in new tab)
3. Ahmed M, Hwang JH, Choi S, Han D. Safety classification of herbal medicines used among pregnant women in Asian countries: a systematic review. BMC Complementary and Alternative Medicine. 2017;17:489. doi:10.1186/s12906-017-1995-6.
Reviews human and preclinical evidence, including potentially harmful botanicals, uterotonic effects, and herbs for which pregnancy safety remains unestablished.Full open-access scientific review (opens in new tab)
4. American Academy of Family Physicians. Over-the-counter medications in pregnancy. American Family Physician. 2023. Section: Over-the-Counter Herbal Supplements in Pregnancy.
Includes clinical safety considerations for aloe, chamomile, echinacea, garlic, ginger, peppermint, raspberry leaf, and valerian.Full clinical review (opens in new tab)
5. University of Texas at El Paso. Herbs to Avoid During Pregnancy. Herbal Safety Program. University of Texas at El Paso.
A botanical reference table identifying plant species, plant parts, forms of use, and reported pregnancy safety concerns. This is a secondary safety resource; some entries reflect traditional or theoretical concerns rather than confirmed human reproductive toxicity.Full botanical safety reference (opens in new tab)
6. National Center for Complementary and Integrative Health. Black Cohosh: Usefulness and Safety. National Institutes of Health. Bethesda, MD.
Describes pregnancy safety concerns, possible hepatic adverse events, product misidentification, and serious neonatal adverse events reported with blue cohosh exposure.Full NIH safety review (opens in new tab)
Additional clinical interpretation
Three distinctions are especially important when using this list in clinical practice.
1. Pregnancy exposure does not automatically mean fetal injury. A single culinary exposure to sage, parsley, thyme, or nutmeg is not equivalent to ingesting concentrated essential oils or extracts.
2. Some commonly listed herbs require a more nuanced interpretation. For example, senna is sometimes included on broad avoid lists, but short-term use of standardized senna products can be acceptable in pregnancy when clinically indicated. Ginger also has clinical evidence supporting treatment of pregnancy-related nausea. Neither should automatically be categorized as a proven abortifacient.
AFP+1
3. Severe maternal toxicity is itself a fetal risk. Pennyroyal oil, poisonous cardiac-glycoside plants, and aristolochic-acid-containing products deserve particular attention even when direct human teratogenicity data are limited.
For further evaluation of a specific exposure, MotherToBaby provides pregnancy-focused toxicology information, including the importance of identifying individual ingredients and formulations.
Fact Sheets – NCBI Bookshelf+1
Research limitation: This is a 50-herb clinical screening list with six full principal references, not 50 individually validated herb-specific studies. Establishing fetal risk for each herb would require separate human pregnancy studies, animal reproductive toxicology, dose-response data, and identification of the actual preparation used.
: Examine these herbs and report if they affect the fertility of a woman or a man, harm the fetus, or hurt pregnancy, or create problems in breast milk. Herbs to examine: cat’s claw, resveratrol, skullcap, banderol, artemisinin, artemeter, artesunate, black walnut, cryptolepis, clove, oregano, cinnamin, garlic, cistus criticus, houttuynia cordota, andrographis, alchornea cordifolia, Japanese knotweed, atemisia, teasel
Reproductive, Pregnancy, Fetal, and Breastfeeding Safety of 20 Herbs and Antimicrobial Compounds
Clinical research review — female fertility, male fertility, embryo-fetal toxicity, pregnancy complications, and lactation
Your list contains 20 named entries, including botanical extracts, isolated plant compounds, and prescription antimalarial medications. These should not all be evaluated under the same safety assumptions.
The most important distinction is between:
- Demonstrated harm: Human or animal evidence of reproductive or developmental toxicity.
- Potential harm: Biological mechanisms or experimental findings that raise concern but do not establish human risk.
- Unknown safety: Inadequate reproductive, pregnancy, or lactation research.
A lack of published evidence of harm is not proof of safety. This is particularly important for botanical combinations used in Lyme disease, Babesia, and Bartonella treatment.
I will distinguish ordinary food exposures from concentrated medicinal doses and prescription antimalarial regimens. For the fertility assessments, findings in experimental animals will be separated from evidence of infertility in humans.
1. Comparative master table
F = female fertility; M = male fertility; P = pregnancy and fetal effects; BM = breastfeeding. “Unknown” means insufficient reliable evidence, not demonstrated safety. Citations are numbered to match the full references.
| # | Agent | Female fertility | Male fertility | Pregnancy / fetus | Breast milk |
|---|---|---|---|---|---|
| 1 | Cat’s claw (Uncaria tomentosa) | Unknown; traditional reproductive concerns | Unknown | Avoid; pregnancy safety concerns | Unknown; avoid medicinal use |
| 2 | Resveratrol | Mixed experimental effects on ovarian function | Mixed experimental effects on sperm | Primate fetal pancreatic changes | No adequate infant safety data |
| 3 | Skullcap (Scutellaria spp.) | Unknown | Unknown | Species-specific safety not established | Unknown |
| 4 | Banderol (Otoba spp., marketed extract) | Unknown | Unknown | No adequate developmental studies identified | Unknown |
| 5 | Artemisinin | Inadequate human fertility data | Inadequate human fertility data | Animal embryotoxicity; human antimalarial data more reassuring | Limited |
| 6 | Artemether | Human infertility not established | Human infertility not established | Effective combination therapy supported in pregnancy | Limited but some reassuring data |
| 7 | Artesunate | Human infertility not established | Human infertility not established | Recommended for severe malaria in pregnancy | Low milk levels in limited study |
| 8 | Black walnut (Juglans nigra) | Unknown | Unknown | Concentrated hull extract inadequately studied | Unknown |
| 9 | Cryptolepis (C. sanguinolenta) | Reduced fertility in animals | Reduced sperm and fertility in animals | Embryonic death, fetal growth restriction and pregnancy loss in animals | Unknown; avoid |
| 10 | Clove (Syzygium aromaticum) | High-dose experimental findings; human effects unknown | Experimental effects vary | Food amounts differ from concentrated oil | Eugenol can enter milk |
| 11 | Oregano (Origanum vulgare) | Unknown at therapeutic doses | Unknown | Food use generally acceptable; oil safety unestablished | Avoid medicinal doses |
| 12 | Cinnamon (Cinnamomum spp.) | Some studies investigate ovulatory benefits | Unknown clinically | Food amounts generally acceptable; concentrated extracts uncertain | Limited data |
| 13 | Garlic (Allium sativum) | No established adverse effect at food doses | No established adverse effect at food doses | Food use generally acceptable; supplements require caution | Flavor compounds enter milk |
| 14 | Cistus creticus | Unknown | Unknown | No adequate pregnancy data | Unknown |
| 15 | Houttuynia cordata | Unknown | Unknown | Insufficient human pregnancy evidence | Unknown |
| 16 | Andrographis (A. paniculata) | Conflicting animal evidence, including implantation concerns | Some animal studies report reduced sperm measures | Possible reproductive toxicity; avoid | Unknown |
| 17 | Alchornea cordifolia | Insufficient reliable evidence | Insufficient reliable evidence | Developmental safety unestablished | Unknown |
| 18 | Japanese knotweed (Reynoutria japonica) | Resveratrol-related effects cannot be assumed for whole extract | Unknown | Avoid medicinal extract; resveratrol findings raise concern | Unknown |
| 19 | Artemisia (Artemisia spp.) | Species-dependent; inadequate human data | Species-dependent; inadequate human data | Some species contain thujone; not interchangeable with antimalarial drugs | Unknown |
| 20 | Teasel (Dipsacus spp.) | Unknown | Unknown | Insufficient safety evidence for concentrated root preparations | Unknown |
The strongest direct reproductive warning in this table concerns cryptolepis, with experimental findings affecting male fertility, female fertility, embryo survival, and fetal growth. The strongest human pregnancy-treatment evidence among these entries concerns appropriately prescribed artemisinin-based antimalarials, not unregulated herbal artemisinin supplements.
PMC+2
2. Most important research findings
Cryptolepis — strongest combined fertility and fetal warning
Cryptolepis sanguinolenta has unusually concerning reproductive toxicology compared with many of the other botanicals listed.
Animal studies summarized in a pharmacological review reported reduced male sperm numbers and fertility, impaired female reproductive outcomes, embryo loss, intrauterine growth restriction, and increased offspring mortality.
One mouse study reported pregnancy loss in approximately 40–46% of exposed animals compared with 0% of controls. These percentages must not be interpreted as human miscarriage rates. Experimental work on cryptolepine also identified abnormal zebrafish embryo development.
PMC+1
Clinical assessment: Avoid during pregnancy and while attempting conception. Breastfeeding safety has not been established.
Andrographis — particularly relevant to male fertility
Experimental research on Andrographis paniculata and andrographolide has produced conflicting results, but some findings are substantial.
Akbarsha and colleagues reported cessation of spermatogenesis and degenerative changes in reproductive tissues in male rats exposed to leaf powder. Subsequent research investigated the role of andrographolide in testicular and epididymal toxicity. Other studies did not reproduce equivalent reproductive effects.
The Botanical Safety Handbook also describes conflicting female fertility and implantation results.
PubMed+2
Clinical assessment: Avoid during pregnancy and use caution in both men and women trying to conceive. Human infertility has not been established.
Resveratrol and Japanese knotweed — fetal development deserves attention
In pregnant nonhuman primates, resveratrol supplementation was associated with improved maternal metabolic parameters but also concerning fetal pancreatic changes.
Roberts and colleagues found a 42% increase in fetal pancreatic mass and substantially increased pancreatic cell proliferation. The long-term consequences were uncertain.
PubMed
These results concern resveratrol exposure in an experimental primate model, not direct testing of Japanese knotweed root extracts in pregnant humans.
Clinical assessment: Avoid high-dose resveratrol supplements and medicinal Japanese knotweed extracts during pregnancy. Human fertility effects remain insufficiently established.
Artemisinin, artemether and artesunate — important exceptions
Artemisinin derivatives can cause embryotoxicity in some animal models, but human pregnancy evidence must be considered separately.
The WHO review supports artemether–lumefantrine for uncomplicated P. falciparum malaria in the first trimester, and current guidance supports its use throughout pregnancy when indicated. Intravenous artesunate is recommended for severe malaria during all trimesters.
World Health Organization+2
There is also a fertility signal in the official Coartem labeling: repeated artemether–lumefantrine administration in female rats reduced pregnancy rates by approximately half in certain experiments. This does not establish infertility in treated women, nor does it justify withholding effective malaria treatment.
DailyMed
For breastfeeding, LactMed reports that artemether–lumefantrine treatment is not by itself a reason to discontinue breastfeeding. Limited measurements following artesunate dosing found low milk concentrations of its active metabolite.
NCBI Bookshelf+1
Clinical assessment: Do not equate prescription antimalarial treatment with unsupervised botanical use. Untreated malaria in pregnancy is potentially life-threatening.
Cat’s claw — pregnancy concern without well-defined human risk
The NIH National Center for Complementary and Integrative Health notes that some pregnancy studies suggest cat’s claw may be unsafe, while breastfeeding safety is poorly understood. No reliable human male or female infertility rate is established.
NCCIH
Clinical assessment: Avoid medicinal use during pregnancy and breastfeeding.
Garlic, oregano and cinnamon — food exposure is not medicinal exposure
These three illustrate why dosage and formulation matter.
Garlic-derived sulfur compounds can alter breast-milk odor. LactMed reports that limited short-term supplementation data have not identified adverse infant outcomes, although concentrated preparations may have antiplatelet effects.
NCBI Bookshelf
Oregano is generally recognized as safe as a food ingredient, but LactMed recommends avoiding quantities above normal food flavoring amounts during breastfeeding because safety data are inadequate. Eugenol, one of its constituents, has been measured in breast milk after dietary exposure.
NCBI Bookshelf
Cinnamon is likewise commonly consumed as food, but concentrated preparations have not been adequately evaluated during breastfeeding. Cassia cinnamon also differs from Ceylon cinnamon in coumarin content.
NCBI Bookshelf
Clinical assessment: Normal culinary exposure is generally not grounds for alarm. Concentrated antimicrobial oils and high-dose extracts should not be presumed equally safe.
3. Full scientific references
These references support the most consequential findings and the clinical distinctions above. For several less-studied botanicals—particularly Banderol, Cistus creticus, Alchornea cordifolia, and teasel—I could not verify adequate human reproductive or lactation studies. I have therefore reported their safety as unknown rather than inventing specific fetal or fertility effects.
Primary studies, official clinical guidance, and specialist evidence reviews. Reference numbers are for this section.
1. Akbarsha MA, Manivannan B, Hamid KS, Vijayan B. Antifertility effect of Andrographis paniculata (Nees) in male albino rat. Indian Journal of Experimental Biology. 1990;28(5):421–426. PMID: 2401516.Full PubMed record (opens in new tab)
2. Akbarsha MA, Murugaian P. Aspects of the male reproductive toxicity/male antifertility property of andrographolide in albino rats: effect on the testis and the cauda epididymidal spermatozoa. Phytotherapy Research. 2000;14(6):432–435. doi:10.1002/1099-1573(200009)14:6%3C432::AID-PTR622%3E3.0.CO;2-I.Full PubMed record (opens in new tab)
3. Roberts VH, Pound LD, Thorn SR, et al. Beneficial and cautionary outcomes of resveratrol supplementation in pregnant nonhuman primates. FASEB Journal. 2014;28(6):2466–2477. doi:10.1096/fj.13-245472.Full research article (opens in new tab)
4. Recht J, Clark R, González R, Dellicour S, editors. Safety of Artemisinin and Non-Artemisinin Antimalarials in the First Trimester of Pregnancy: Review of Evidence. Geneva: World Health Organization; 2024. ISBN: 978-92-4-006940-4.WHO full report (opens in new tab)
5. UK Teratology Information Service. Use of Artemisinin and Artemisinin Derivatives in Pregnancy. Version 3. Newcastle upon Tyne: UKTIS; November 2025.Full pregnancy safety monograph (opens in new tab)
6. U.S. National Library of Medicine. Artesunate. Drugs and Lactation Database (LactMed). Bethesda, MD: National Library of Medicine; updated June 15, 2025.Full LactMed reference (opens in new tab)
7. U.S. National Library of Medicine. Artemether and Lumefantrine. Drugs and Lactation Database (LactMed). Bethesda, MD: National Library of Medicine; updated July 15, 2025.Full LactMed reference (opens in new tab)
8. U.S. National Library of Medicine. Garlic. Drugs and Lactation Database (LactMed). Bethesda, MD: National Library of Medicine; updated May 15, 2026.Full LactMed reference (opens in new tab)
9. U.S. National Library of Medicine. Oregano. Drugs and Lactation Database (LactMed). Bethesda, MD: National Library of Medicine; updated November 15, 2024.Full LactMed reference (opens in new tab)
10. U.S. National Library of Medicine. Cinnamon. Drugs and Lactation Database (LactMed). Bethesda, MD: National Library of Medicine; updated October 15, 2026.Full LactMed reference (opens in new tab)
11. National Center for Complementary and Integrative Health. Cat’s Claw: Usefulness and Safety. Bethesda, MD: National Institutes of Health.NIH clinical safety review (opens in new tab)
12. National Institutes of Health, Office of Dietary Supplements. Dietary Supplements and Life Stages: Pregnancy—Health Professional Fact Sheet. Bethesda, MD: NIH.Full NIH pregnancy reference (opens in new tab)
13. American Herbal Products Association. Botanical Safety Handbook. 2nd ed. Edited by Zoe Gardner and Michael McGuffin. Boca Raton, FL: CRC Press; 2013.
This reference contains detailed monographs on botanical safety, including conflicting reproductive findings for andrographis.
14. U.S. Food and Drug Administration. Coartem (Artemether and Lumefantrine) Tablets: Prescribing Information. Sections 8.1, 8.2, and 8.3. DailyMed, National Library of Medicine.Full prescribing information (opens in new tab)
15. Centers for Disease Control and Prevention. Malaria Treatment for Pregnant Women. Atlanta, GA: CDC; updated August 17, 2026.CDC pregnancy treatment recommendations (opens in new tab)
16. Centers for Disease Control and Prevention. Treatment of Severe Malaria. Atlanta, GA: CDC; updated August 17, 2026.CDC severe malaria treatment recommendations (opens in new tab)
17. Phytochemical and Pharmacological Review of Cryptolepis sanguinolenta (Lindl.) Schlechter. 2017. Open-access scientific review covering pharmacology, male and female reproductive effects, embryotoxicity, and maternal toxicity.Full scientific review and bibliography (opens in new tab)
18. Cryptolepine, the Main Alkaloid of the Antimalarial Cryptolepis sanguinolenta (Lindl.) Schlechter, Induces Malformations in Zebrafish Embryos. 2019. Experimental developmental toxicology research.Full research article (opens in new tab)
4. Clinical conclusions
For reproductive counseling, I would prioritize the evidence as follows:
| Clinical question | Most important findings |
|---|---|
| Which agents have the clearest animal evidence of reduced male fertility? | Cryptolepis and andrographis |
| Which has evidence of reduced female fertility or pregnancy success? | Cryptolepis; artemether–lumefantrine in animal studies; conflicting andrographis findings |
| Which have particularly concerning embryo-fetal findings? | Cryptolepis, high-dose resveratrol, and artemisinin derivatives in animal models |
| Which have supportive human pregnancy-treatment evidence? | Prescription artemether–lumefantrine and artesunate for malaria |
| Which have some direct breast-milk exposure data? | Artesunate, garlic, oregano constituents; modeling data for artemether–lumefantrine |
| Which are especially poorly studied? | Banderol, Cistus creticus, Alchornea cordifolia, teasel, and several other concentrated botanical extracts |
One final distinction matters: Breast-milk transfer, changes in milk production, and harm to a breastfed infant are three separate outcomes. Demonstrating that a compound enters milk does not prove infant toxicity, while the absence of infant toxicity reports does not establish safety.
For a woman who is pregnant, trying to conceive, or breastfeeding, I would not use cryptolepis or andrographis medicinally on the current reproductive evidence. I would also avoid the poorly characterized concentrated herbal extracts unless a reliable benefit-risk assessment becomes possible. By contrast, clinically indicated treatment of malaria with recommended antimalarials should not be delayed because of animal reproductive findings.