Salbutamol has been shown to improve muscle weight in rats  and anecdotal reports hypothesise that it might be an alternative to clenbuterol for purposes of fat burning and muscle gain, with multiple studies supporting this claim.     Abuse of the drug may be confirmed by detection of its presence in plasma or urine, typically exceeding 1000 µg/L. The window of detection for urine testing is on the order of just 24 hours, given the relatively short elimination half-life of the drug,    estimated at between 5 and 6 hours following oral administration of 4 mg. 
A version of this article appears in print on October 13, 2013, on page A 1 of the New York edition with the headline: The Soaring Cost of a Simple Breath. Get Free Email Alerts on These Topics Asthma Drugs (Pharmaceuticals) Prices (Fares, Fees and Rates) Series Inside Health » Too Hot to Handle Arts » The Harmony of Liberty Opinion » Should Beach Privatization Be Allowed? Room for Debate asks whether shorefront homeowners should have to open their land to all comers.