Red rice yeast has been used for centuries in China as a medicine. The active ingredient in red yeast is Monacilin K (also known as lovastatin).
You may have heard of the name statins. Statin drugs are prescribed to treat high cholesterol. Statins work by inhibiting the action of an enzyme needed to make cholesterol, so that the body's cholesterol levels can fall.
Lovastatin, found in red rice yeast, works in the same way as other strains - by inhibiting the enzyme needed to make cholesterol. This gives red rice yeast a cholesterol-lowering effect.
However, it is important to add that statins would have various side effects - due to the fact that this enzyme has several roles in addition to cholesterol production (it plays a role in muscle regeneration and is thought to be found in liver cells). Therefore, statin therapy may be associated with muscle pain, muscle weakness, fatigue, increased liver enzyme levels and worsening blood glucose levels.
Red rice yeast, due to its statin content, can cause the same side effects. It should therefore only be used when a doctor has recommended the use of a cholesterol-lowering statin. Consult a doctor for the correct dosage.