The signs and symptoms of a cold -- coughing, sneezing, stuffy nose, sore throat, headache, watery eyes and fever -- can make you miserable. The common cold, which is an upper respiratory tract infection, can be caused by one of many types of rhinoviruses. A cold typically lasts from seven to 10 days before clearing up on its own. The common cold has no cure, but products are available to treat symptoms. Before taking supplements that may help shorten the duration of your cold, talk to your doctor.
Vitamin C, or L-ascorbic acid, is one of the essential water-soluble vitamins, meaning it is not manufactured by your body, so it must be obtained in your diet or through supplementation. It is important for protein metabolism and synthesis of collagen and some neurotransmitters. While vitamin C doesn't appear to prevent colds, it may be helpful in shortening the duration of symptoms if taken before they appear. The Office of Dietary Supplements states the anti-histamine-like action of high doses of vitamin C may be responsible for this effect.
Zinc is an essential nutrient that also must be obtained in the diet or via supplementation. Zinc has strong antioxidant properties that protect cells from damage from free radicals. It is also needed for proper blood clotting, immune function, sensory perceptions and thyroid and insulin functioning. Zinc supplements are often used to shorten and lessen the symptoms of a cold, particularly those caused by a rhinovirus. A study performed at the Post-Graduate Institute of Medical Education and Research in Chandigarh, India, found zinc to be effective in shortening the severity and duration of cold symptoms when it was taken within 24 hours of the symptoms appearing.
Echinacea, also known as the coneflower, is a perennial plant that produces purple flowers resembling daisies. Echinacea has a wealth of active compounds that appear to have some immune-stimulating properties. Echinacea activates immune cells called macrophages, which gobble up microbes such as viruses and bacteria, and it increases production of interferon in response to viral infections. Phyllis A. Balch, author of "Prescription for Herbal Healing," states that while some controversy surrounds its effectiveness, echinacea may be taken at the onset of cold symptoms to shorten their duration and severity.
Garlic, or allium sativa, is a perennial plant with an underground bulb that has been used for centuries in cooking and as an herbal medicine. Garlic contains the sulphur-containing compound allicin, which is responsible for its pungent odor and its medicinal properties. Garlic contains a wealth of antioxidants, which strengthen the immune system and help prevent free radicals from damaging cells. Garlic also has anti-viral properties. The University of Maryland Medical Center states garlic supplements may be helpful in reducing the duration of cold symptoms.