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The active substance furosemide is marketed under the brand name Lasix by Aventis Pharma. Furosemide is a grinding diuretic. The intake promotes excretion of water, potassium, sodium and chlorine compounds. It is used by athletes for weight category adjustment and bodybuilders before competitions to minimize water concentrations within the muscles. The result for athletes is a rapid weight loss and for bodybuilders a hard and dry appearance of the muscles.

This remedy can be dangerous because it can dehydrate and cause severe potassium deficiency (hypokalemia) as well as severe sodium deficiency (hyponatremia). This results in a considerable disturbance of the electrolyte balance. Lasix is one of the strongest diurethanes and has already cost the lives of some athletes.

Effects (according to the manufacturer): dissolution of water accumulations in the tissue and the abdomen, if disturbances of the mineral household by an derailment of the adrenal function are present and other drainage drugs remain ineffective
Dissolution of water accumulations in the tissue and / or in the lungs due to heart muscle weakness
Dissolution of water accumulations in the abdomen as a result of a liver function disorder
Side effects: gastrointestinal tract complaints, nausea, vomiting, dyspepsia, diarrhea, potassium deficiency, sodium deficiency, dehydration, erection problems (due to blood pressure reduction), muscle cramps, circulatory collapse, dizziness, weakness


Lasix (Furosemide) is available as a tablet or intravenous solution. The effect of the tablets occurs after about an hour and lasts 3-4 hours. The intravenous solution acts immediately.


As a matter of fact, bodybuilders take a half or whole 40 mg tablet and wait to see how it works. Some repeat this procedure at intervals of a few hours 1-2x.

The dosage information given here is not intended as a dosage recommendation or medical advice. These are statements by bodybuilders who have used or used these active ingredients. The dosages should never be regarded as generally valid. If you are using the idea of using steroids or similar, ask a doctor or pharmacist.

Black market prices / availability:

Furosemide is moderately available on the black market. The prices are between 0,40 and 1,20 euro per tablet with 125mg active substance. An ampoule injection solution with 40 mg active ingredient costs between 3 and 4 euros.

Furosemide products are readily available on the black market.


Counterfeits are rare, occasionally one finds underdosed products.


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Trade name / manufacturer:

Lasix / Aventis Pharma
Furorese / HEXAL AG
Impugan / Team medica AG
Oedemex / Mepha Pharma AG

Other trade names: Frusid, Frusol, Frudix, Furosedon, Frusemid, Furosemide, Furosemidum, Furo-Bazaar, Furodrix, Fursol, Diurapid, Furanthril, Furo, Furobeta, Furogamma, Furomed, Furosal, Fusid, Jufurix, Durafuride, Desdemin, Discoid, Dryptal , Errolon, Eutensin, Frumex, Frusemide, Frusetic, Frusid, Fulsix, Fuluvamide, Furesis, Furosedon

Chemical information:Furosemid - Furosemide - Molekularformel

Molecular formula: C12H11ClN2O5S
Molecular weight: 330.744 g / mol
Monoisotopic mass: 330.007721 Da

Half-life: approx. 90 – 100 minutes

CAS number: 54-31-9

4-chloro-2-furfurylamino-5-sulfamoyl-benzoic acid; 4-chloro-2- (furan-2-ylmethylamino) -5-sulfamoylbenzoic acid
4-chloro-2 – [(2-furylmethyl) amino] -5-sulfamoylbenzoic acid