How to Tell Real Methylene Blue from Fake or Low-Quality Product

Because methylene blue is sometimes diluted or substituted, here are practical ways to identify quality:

1. Appearance of the Powder

• Genuine methylene blue powder looks dark green to bronze metallic crystals

• It does NOT look bright blue as a dry powder

• Very light blue powder can indicate low purity or textile dye grade

2. Colour in Water

• When dissolved, real methylene blue produces a deep, intense royal blue colour

• The solution should be clear and evenly coloured

• Cloudiness or sediment may indicate impurities

3. Solubility Test

• High-grade methylene blue dissolves easily in distilled water

• Significant residue suggests fillers or contamination

4. Vitamin C (Ascorbic Acid) Reduction Test – Simple Authenticity Check

This is a reliable redox test:

1. Prepare a dilute blue methylene blue solution.

2. Add a small amount of Vitamin C (ascorbic acid) powder.

3. Genuine methylene blue will turn clear (colorless) as it is reduced to leucomethylene blue.

4. Shake the container — exposure to oxygen may gradually turn it blue again.

If the solution does not turn clear after adding vitamin C, it may not be genuine methylene blue or may be heavily diluted.

5. Staining Strength

• A very small amount should strongly stain paper or fabric

• Weak staining power suggests dilution

6. Smell

• Pure methylene blue has little to no strong odour

• Strong chemical smell may indicate contamination