Clenbuterol is known to be a powerful fat-burner and an effective weight loss drug used mostly by weight lifters and bodybuilders. It boosts energy by increasing the metabolism of fats while protecting muscle gains. It is available in the market as a liquid formulation, gel formulation, as a bulk powder, as pill tablets and as spray. You can find clenbuterol spray or commonly called as “clen spray pens” in areas where the pill tablets are not allowed due to legal restrictions. Although clen spray pens are usually used as a bronchodilator to make breathing easier, these are not officially intended for human use and are meant to be prescribed for certain livestock such as horses. There are some bodybuilders who buy these clen spray pens in underground laboratories but it has become easier now to buy clenbuterol pills for personal consumption via online.