People throughout the world use fenugreek and thyme as both spices and medicinal herbs. Fenugreek seeds contain properties that may help to treat a wide range of conditions like high cholesterol, diabetes, cardiovascular diseases and constipation. Thyme's oil extract may help to treat fungal infections and respiratory conditions, and is sometimes added to mouthwashes and toothpastes for preventing gingivitis. Both fenugreek and thyme are generally safe, but they do pose a few specific health risks.
Taking thyme or fenugreek may cause certain gastrointestinal side effects. If you ingest thyme’s volatile oil, you could experience vomiting, as well as dizziness and difficulty breathing, warns the University of Michigan Health System. You should use thyme oil only topically and not internally. Also, if taking high doses of fenugreek seeds, specifically more than 100 g daily, you may experience nausea and gastrointestinal upset.
Fenugreek may be unsafe to take during pregnancy due to specific risks of miscarriage. A study in guinea pigs found that taking fenugreek extracts can stimulate the uterus to contract, notes the University of Pittsburgh Medical Center. This poses a potential danger to pregnant women, warns the University of Michigan Health System.
If you take medications to treat diabetes, you should consult your physician before taking fenugreek. Fenugreek can lower your blood glucose levels, potentially causing hypoglycemia, warns the University of Pittsburgh Medical Center. Fenugreek may be especially dangerous when combined with blood sugar-lowering diabetes medications or therapies, because the combination could cause your blood sugar levels to become dangerously low.
You may be sensitive to thyme oil’s properties. Thyme oil used on the skin or as a mouthwash can cause irritations or allergic reactions in some people, notes the University of Michigan Health System. If you experience skin rashes or other irritations from thyme oil, stop using it right away.