Clenbuterol Hydrochloride or Clenbuterol has been a safe and effective option for thousands of amateur & professional athletes who want to get in top shape and improve performance. This fat loss drug is also known as Clen, Spiropent, and Ventipulmin and can be best described as a potent ß2 agonist with some structural and pharmacological similarities to Epinephrine and Salbutamol.