Editing Herbal tea (section)

== Health risks ==
{{See also|List of herbs with known adverse effects|Tea bag#Plastics}}

While most herbal teas are safe for regular consumption, some herbs have [[toxin|toxic]] or [[allergy|allergenic]] effects. Among the greatest causes of concern are:
* [[Comfrey]], which contains [[alkaloid]]s which may be harmful to the [[liver]] from chronic use, and particularly is not recommended during pregnancy or when [[prescription drug]]s are used; comfrey is not recommended for oral use.<ref>{{cite web|title=Comfrey|url=https://www.drugs.com/mtm/comfrey.html|publisher=Drugs.com|access-date=5 January 2018|date=3 January 2018}}</ref>
* [[Lobelia]], which contains alkaloids and has [[traditional medicine]] uses for smoking cessation, may cause nausea, vomiting, or dizziness at high doses.<ref>{{cite web|title=Lobelia|url=https://www.drugs.com/npp/lobelia.html|publisher=Drugs.com|access-date=5 January 2018|date=3 January 2018}}</ref>

Herbal teas can also have different effects from person to person, and this is further compounded by the problem of potential misidentification. The deadly [[foxglove]], for example, can be mistaken for the much more benign (but still relatively toxic to the liver) comfrey. Care must be taken not to use any [[poisonous plants]].

The US does not require herbal teas to have any evidence concerning their efficacy, but does treat them technically as food products and require that they be safe for consumption.

Fruit or fruit-flavored tea is usually acidic and thus may contribute to erosion of [[tooth enamel]].<ref name="O'Toole2018">{{cite journal |last1= O'Toole|first1= S.|last2= Mullan|first2= F.|title= The role of the diet in tooth wear|journal= British Dental Journal|volume= 224|issue= 5|pages= 379–383|year= 2018|doi= 10.1038/sj.bdj.2018.127|pmid= 29471309|s2cid= 3797429|url= https://kclpure.kcl.ac.uk/portal/en/publications/the-role-of-the-diet-in-tooth-wear(7a470d3f-b003-4383-831e-24f14fcdd600).html}}</ref>

=== Adverse herb–drug interactions ===
{{See also|Grapefruit–drug interactions|Cytochrome P450|label 2=Cytochrome P450 (CYP)}}
Some phytochemicals found in herbs and fruits can adversely interact with others and over the counter or prescription medications, among other ways by affecting their metabolism by the body. Herbs and fruits that inhibit or induce the body's Cytochrome P450 enzyme complex function can either cause the drug to be dangerously ineffective, or increase its effective absorbed dose to potentially toxic levels, respectively. Best known examples of adverse herb‑drug interactions are [[grapefruit]] or [[Hypericum perforatum|St John's wort]], contraindicated for several medications including [[Paxlovid]] and [[oral contraceptives]], but other herbs also affect the CYP enzyme family, showing herb‑drug interactions.<ref>{{Cite journal |last1=Zuo |first1=Hua-Li |last2=Huang |first2=Hsi-Yuan |last3=Lin |first3=Yang-Chi-Dung |last4=Cai |first4=Xiao-Xuan |last5=Kong |first5=Xiang-Jun |last6=Luo |first6=Dai-Lin |last7=Zhou |first7=Yu-Heng |last8=Huang |first8=Hsien-Da |date=2022-01-14 |title=Enzyme Activity of Natural Products on Cytochrome P450 |journal=Molecules |language=en |volume=27 |issue=2 |pages=515 |doi=10.3390/molecules27020515 |issn=1420-3049 |pmc=8779343 |pmid=35056827 |doi-access=free }}</ref><ref>{{Cite journal |last1=Cho |first1=Hyun-Jong |last2=Yoon |first2=In-Soo |date=2015 |title=Pharmacokinetic Interactions of Herbs with Cytochrome P450 and P-Glycoprotein |journal=Evidence-Based Complementary and Alternative Medicine |language=en |volume=2015 |pages=1–10 |doi=10.1155/2015/736431 |issn=1741-427X |pmc=4302358 |pmid=25632290 |doi-access=free }}</ref><ref>{{Cite journal |last1=Smith |first1=Dallas J. |last2=Bi |first2=Huichang |last3=Hamman |first3=Josias |last4=Ma |first4=Xiaochao |last5=Mitchell |first5=Constance |last6=Nyirenda |first6=Kumbukani |last7=Monera-Penduka |first7=Tsitsi |last8=Oketch-Rabah |first8=Hellen |last9=Paine |first9=Mary F. |last10=Pettit |first10=Syril |last11=Pheiffer |first11=Wihan |last12=Van Breemen |first12=Richard B. |last13=Embry |first13=Michelle |date=2023-07-12 |title=Potential pharmacokinetic interactions with concurrent use of herbal medicines and a ritonavir-boosted COVID-19 protease inhibitor in low and middle-income countries |journal=Frontiers in Pharmacology |volume=14 |doi=10.3389/fphar.2023.1210579 |issn=1663-9812 |pmc=10368978 |pmid=37502215 |doi-access=free }}</ref>

=== Contamination ===
{{See also|Health effects of pesticides}}
Depending on the source of the herbal ingredients, herbal teas, like any crop, may be contaminated with [[pesticide]]s or [[heavy metals]].<ref name=NaithaniKakkar2004 /><ref>{{cite journal | pmid = 16228893 | year = 2005 | last1 = Naithani | first1 = V | last2 = Kakkar | first2 = P | title = Evaluation of heavy metals in Indian herbal teas | volume = 75 | issue = 1 | pages = 197–203 | doi = 10.1007/s00128-005-0738-4 | journal = Bulletin of Environmental Contamination and Toxicology| bibcode = 2005BuECT..75..197N | s2cid = 41011619 }}</ref>
According to Naithani & Kakkar (2004), "all herbal preparations should be checked for toxic chemical residues to allay consumer fears of exposure to known neuro-toxicant pesticides and to aid in promoting global acceptance of these products".<ref name=NaithaniKakkar2004>{{cite journal | pmid = 16268119 | year = 2004 | last1 = Naithani | first1 = V | last2 = Kakkar | first2 = P | title = An evaluation of residual organochlorine pesticides in popular Indian herbal teas | volume = 59 | issue = 8 | pages = 426–30 | doi = 10.3200/AEOH.59.8.426-430 | journal = Archives of Environmental Health | s2cid = 31026817 }}</ref>