Canthaxanthin

Studies in people

• No harm found

  Mouth cell changes in chewers²

  In people who chew betel nut and tobacco, canthaxanthin did not change the number of mouth cells with damaged DNA.

• Concern

  Eye crystals³

  People who never took canthaxanthin medicines still had gold crystals in their eyes, and canthaxanthin in food may be the cause.

Animal and lab studies only

• Concern

  Eye damage from food colouring⁴

  Canthaxanthin can build up as crystals in the eye, and lab studies show it may harm nearby blood vessels.

• Concern

  Medicine processing in the liver⁵

  In lab studies, canthaxanthin weakly slowed two liver enzymes that help break down some medicines.

• Concern

  How the body handles medicines⁶

  In lab studies, canthaxanthin weakly slowed two liver enzymes that break down some medicines.

How it’s made and used

• Food colouring intake¹

  Canthaxanthin is a food colouring, and scientists checked how much people get from eggs; levels found were within the accepted daily limit.

• Flesh colour in farmed trout⁷

  Canthaxanthin fed to trout builds up in their flesh, but not enough to match supplement benefits.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.

Expert panels that weigh all the research. Shown for context: the signal at the top does not count them.

• UN and WHO food additive experts (JECFA), 1995

  Acceptable daily intake: up to 0.03 mg per kg of body weight.