Synthetic Urine Composition

Real human urine is very complex liquid, which consist of about 91-96% of water and the rest includes both organic and inorganic substances in approximate ratio 7/5. Most of them are either the leftovers of foods and drinks people consume or waste products of the cellular metabolism.

Organic and inorganic components

Among the organic components the most important and indispensable substances are uric acid, creatinine (hydrated form of creatine), and urea. Since urea composes about 95% of urine nitrogen, it is not necessary to add uric acid in composition, but nowadays most commercial products made specially for use in drug tests include it, because all drug testing labs test for uric acid and reject samples without it.

The main inorganic components are sulfates, phosphates, chlorides and ammonia. Ammonia, which is a toxic product of breakdown of urea, makes up very small part of human urine, so its presence in synthetic one is not required, but desirable.

Synthetic urine formula

Since the exact chemical structure of human urine varies from person to person and depends on such factors as diet, health and physical condition, the synthetic urine also does not have standard precise formula. Every manufacturer has its own patented composition. Below is one of the possible variations:

• Organic components:
  
  • 6 – 9 g/L of urea
  • 0.5 – 3 g/L of creatinine
• Inorganic components:
  
  • 2 g/L of potassium chloride
  • 0.5 g/L of magnesium chloride
  • 0.25 g/L of calcium chloride
  • 2 g/L of sodium sulfate
  • 0.85 g/L of ammonium phosphate
  • 0.85 g/L of ammonium diphosphate

In the simpler composition for students learning only 4 components may be used: urea, sodium chloride, potassium chloride and sodium phosphate. This will give liquid similar to urine, which can be used in laboratory experiments, but not good enough for using in drug tests.


The specific gravity of synthetic urine must be about 1.003–1.035 and pH between 5 and 10. When used, the temperature must be between 90 – 100 °F to imitate the temperature of real human urine.

Additional components

Besides the above substances, synthetic urine can also have some extra components, for example preservatives, hormones (estrogen or testosterone), and coloring agents, such as yellow dyes, beta carotene, B vitamins etc.

Synthetic urine has evolved in many ways and today we use it in various areas, for example scientists widely use it in labs for studies and calibration of drug testing equipment. For calibration additional drugs and drug metabolites maybe added to ensure the equipment is working properly, for example THC (the main chemical substance of marijuana), deuterated THCA, morphine, heroin, amphetamine, PCP, cocaine, ethanol, benzoyl ecgonine, and the like.

In addition, there are risk that other substances like acetylsalicylic acid (also known as aspirin) can be mistaken for drugs and produce false-positive result, so they also can be added into synthetic urine and used as an alternative negative control.

Storage forms

There are 3 storage forms of synthetic urine: normal, concentrated and powdered. The powdered form can contain some heat activator - the substance that generates heat when mixed with water in order to get the desired temperature of liquid. In case of concentrated and normal form, heat activator is always stored separately and added immediately before use.

When concentrated, the synthetic urine can be in the form of paste, gel, or liquid. It can also include some carrier, like pectin matrix, which is water-soluble and does not give unusual readings during urine test.