Fenugreek usually has no adverse side effects whatsoever and is quite safe, unless you are allergic to it. Some studies have also shown a relation between fenugreek and developing asthma. You should have a skin test done first.

Fennel is usually contraindicated during pregnancy, and is quite safe.

Bromelain is generally considered safe. Some people may be allergic to bromelain, and it may cause bleeding when taken with anticoagulant (blood thinning) medications. Some practitioners advise caution when administering bromelain to people with high blood pressure.

Echinacea is non-toxic but also associated with the development of asthma. In Australia for example, five patients were administered a skinprick of echinacea each. Two patients suffered anaphylaxis and a third had an acute asthma attack 10 minutes after their first ever dose of echinacea. The fourth patient suffered recurrent episodes of mild asthma each time echinacea was ingested, and the fifth developed a rash within 2 days of ingestion which recurred when rechallenged. Don't use with steroids, amiodarone, methotrexate, or ketoconazole.