Questionable side effects: Officials have warn that taking echinacea can lead to side effects like, swelling of the mouth and tongue, anaphylactic shock, fever, nausea, vomiting, stomach pain, diarrhea, constipation, sore throat, dry mouth, headache, numbness or tingling of the tongue, dizziness, sleep problems, confusion, joint pain and muscle aches, according to the Medicines and Healthcare Products Regulatory Agency (MHRA).
Sources:
http://umm.edu/health/medical/altmed/herb/echinacea
http://umm.edu/health/medical/altmed/herb-interaction/possible-interactions-with-echinacea
https://nccih.nih.gov/health/echinacea/ataglance.htm#intro
http://www.askdrsears.com/topics/feeding-eating/family-nutrition/foods-to-boost-immunity/frequently-asked-questions-about-echinacea
http://www.telegraph.co.uk/news/health/news/9487557/Dont-give-children-echinacea-warns-MHRA.html
