Trimethylaminuria (TMAU), also known as fish odor syndrome or fish malodor syndrome, is a rare metabolic disorder that causes a defect in the normal production of an enzyme named flavin-containing monooxygenase 3 (FMO3). When FMO3 is not working correctly or if not enough enzyme is produced, the body loses the ability to properly convert trimethylamine (TMA) from precursor compounds in food digestion into trimethylamine oxide (TMAO), through a process called N-oxidation. Trimethylamine then builds up and is released in the person's sweat, urine, and breath, giving off a fishy odor. Primary trimethylaminuria is caused by genetic mutations that affect the FMO3 function of the liver. Symptoms matching TMAU can also occur when there is no genetic cause, yet excessive TMA excreted - this has been described as secondary trimethylaminuria (TMAU2). TMAU2 can be caused simply by a precursor overload (ingesting too many dietary TMA precursors), hormonal issues related to menstrual cycles, liver damage, or liver and kidney failure. As a symptom rather than a disease, TMAU2 is temporary and will resolve as the underlying cause is remedied (in the instance of menstrual related TMAU2, at menopause)


Trimethylamine is most noticeable in urine, as it is captured, concentrated and released in intervals. Fishy smelling urine is a primary identifying symptom in infant children (Trimethylaminuria literally meaning "trimethylamine in urine").

Trimethylamine is also released in the person's sweat, reproductive fluids, and breath, and can give off a fishy odor when the concentration of trimethylamine is high enough to be detected. The intensity of the smell is directly correlated with the concentration of trimethylamine in the bloodstream.

Some people with trimethylaminuria report having a strong odor all the time, but when in a clinical setting most have only moderate to no smell, depending on diet and the severity of their FM03 mutation. In a study by Wise PM, of 115 identified tmau subjects, 0% had a smell detectable at a social distance and only 5% had some minor malodour when sniffing their palms. After a choline challenge load test (intentionally ingesting a TMA precursor) only 10% expressed a smell at a social distance, suggesting that those that produced odour had a more severe form of FMO3 impairment. Smell events are often sporadic and episodic in nature (based on diet over the previous 24 hours), making it often difficult to diagnose by smell alone.

Individuals with this condition do not have any physical symptoms, and they typically appear healthy.

The condition seems to be more common in women than men, for unknown reasons. Scientists suspect that such female sex hormones as progesterone and estrogen aggravate the condition. According to several reports, the condition worsens around puberty. In women, symptoms may worsen just before and during menstrual periods, after taking oral contraceptives, and around menopause.


Homoeopathy today is a rapidly growing system and is being practiced all over the world. It strength lies in its evident effectiveness as it takes a holistic approach towards the sick individual through promotion of inner balance at mental, emotional, spiritual and physical levels. When  is concerned there are many effective medicines available in Homoeopathy , but the selection depends upon the individuality of the patient , considering mental and physical symptoms

Few homoeopathic medicine can be thought of in the management  of fish odor syndrome are:

mag carb, mag mur., rheum., etc.