The active ingredient of Sudafed is 120 milligrams of pseudoephedrine HCI, whereas the inactive ingredients include candelilla wax, magnesium stearate, hypromellose, polyethylene glycol, microcrystalline cellulose, povidone and titanium dioxide, according to RxList. Sudafed's official website adds shellac, FD&C blue no.1 aluminum lake and talc as inactive ingredients. Pseudoephedrine HCl is a nasal decongestant.
Pseudoephedrine works by narrowing blood vessels to decrease inflammation to bring temporary relief from cold symptoms in the nose and sinuses, according to WebMD. Sudafed also eases symptoms of hay fever, allergies, influenza and bronchitis. WebMD warns that pseudoephedrine does not shorten the time of a common cold, nor does it cure a cold. WebMD encourages patients to precisely follow instructions on the packaging.
Sudafed informs users that federal regulations require consumers to show identification when purchasing the decongestant. Pseudoephedrine products are kept behind the counter of pharmacies, and consumers must sign a log book upon buying the product. Procedures vary by state, but there are currently five different Sudafed products kept behind the counter at pharmacies.
David Whelan, regular health contributor to Forbes magazine, notes that the reason for purchase limits on drugs like Sudafed is because of illegal meth production in the United States. Despite new regulations in 2006, meth makers in the United States have nearly returned to pre-2006 levels due to imported meth from Mexico. Whelan cites statistics in 2012 that state Mexican meth was preferred on the illegal drug market because its purity was better than American versions of the substance.