Which herb is an immunostimulant?

• A. Ginkgo biloba
• B. Milk thistle
• C. Echinacea purpurea
• D. Omega-3 fish oil

Answer: (C)

Immunostimulants are substances that boost the body's immune response. The herb echinacea purpurea is commonly used for this purpose. It is thought to enhance immune function by activating immune cells such as macrophages and increasing the production of cytokines, which help coordinate the body's defense against infections. In practice, echinacea has been used to help prevent or lessen the severity and duration of upper respiratory infections when started early.

Some important context: evidence on effectiveness is mixed, and benefits may be modest or vary among individuals. Because it stimulates the immune system, it’s usually recommended for short-term use and may not be suitable for everyone. It should be avoided in people with autoimmune diseases, those who have severe allergies to daisies or ragweed, and individuals taking immunosuppressants or certain vaccines, unless a clinician approves.

Ginkgo biloba focuses mainly on circulation and cognitive function and carries antiplatelet risks, not immunostimulation. Milk thistle is known for liver protection rather than boosting immune activity. Omega-3 fish oil modulates inflammation and has various health benefits, but it isn’t classified as an immunostimulant.