Echinacea should be taken at the first sign of symptoms for maximum effectiveness (good to know in the future) but it's never too late. It should NOT be taken daily, but only during the course of the infection. It is not effective as a daily supplement. My favored form of administration is an infusion (tea). Bring pure water to a rolling boil, pour over loose echinacea flowers in a non-metal pot (or just use a bag if you must). Allow to steep, covered, for 15 minutes. May add a TOUCH of honey to taste but definitely don't "sweeten" it. You can also steep it with a slice of fresh ginger for taste and immune support. Echinacea is contraindicated for persons with allergy to daisies/chamomile, as it is a member of the daisy family. Sage is another herb that is great for a cold. Make a tea with it. It tastes awful but works great. I would say absolutely skip the vitamin C megadoses. I recommend fresh pressed carrot juice (perhaps with a bit of apple and celery to make it more palatable for your brother) If you don't have a juicer, check with your local mall- most have a juice bar. They'll be glad to make your juice for you. I also recommend making broth from fresh bones, and adding lots of fresh garlic in the last few minutes of cooking. The allicin in garlic is a strong anitbacterial, antiviral, antifungal. Definitely skip the antibiotics. Stacie