Echinacea purpurea belongs to the daisy family. The aerial parts and roots go into teas, tinctures, capsules, and extracts. People turn to this plant when they feel the first signs of a cold. Evidence on whether it shortens or eases symptoms is split. Most traditions use it for short bursts, not daily upkeep.
Tinctures are usually started early, right when symptoms appear. Capsules and teas are common. Product labels generally point to short-term use.
Skip echinacea if you have an autoimmune disorder or take immunosuppressant drugs. Allergic reactions can happen, especially among people sensitive to ragweed, daisies, and other Asteraceae family plants. Safety data for pregnancy and breastfeeding is thin, so use extra caution there.