PEG stands for polyethylene glycols or polyethylene glycols, produced from water and condensed ethylene oxide, with various acts in medical, pharmaceutical, human food, animal feed, cosmetics and other fields. PEGs undergo thorough testing and specific safety assessment studies are required before they are placed on the market and are therefore generally considered safe. In the chemical production of PEG, impurities and production by-products such as ethylene oxide and 1,4-dioxane may be present, which are considered by the scientific literature to be known carcinogens. It is required by product control authorities that ethylene oxide and 1,4-dioxane are removed before they are mixed into formulations. Therefore, it is not correct to demonise the entire PEG category and try to avoid it as I see in some cosmetic product labels that flaunt 'PEG free', as the genotoxic hazard should be excluded upstream of the problem. At the very least, one would have to wonder if some companies might still be using non-certified PEGs, but the controls, at least in Europe and the United States, are quite strict.
Since the PEG (1) family is numerous and is found in many cosmetic, cleaning and medicinal products and others, we need a cognitive premise on the subject that is rather complex from the point of view of safety because these products not only come into contact with the skin but, as in the case of medicine, they are also ingested.
PEG or polyethylene glycols polymerise the condensed ethylene oxide and water and are called polyethylene glycols, but in reality, they are complex chemical components, polymers bound together. For example, plastic is polyethylene and has a hard consistency, while polyethylene aggregated to the glycol forms a liquid.
The number that appears after the initials PEG represents the molecular weight and the higher this number is, the less it penetrates the skin.
Here below are some studies in Medicine that refer to the use of PEG Polyethylene glycol in various fields.
Intestine
Polyethylene glycol with or without electrolytes is effective for the treatment of functional constipation, both in adults and in paediatric patients, with great safety and tolerability. These preparations are the most effective osmotic laxatives (more than lactulose) and are the first-line treatment for functional constipation in the short- and long-term. They are as effective as enemas in faecalomas, avoid the need for hospitalisation and are well tolerated by patients (especially when given without electrolytes) (2).
In the preparation for colonoscopy, polyethylene glycol tablets confirmed efficacy, acceptability, tolerance and safety similar to those of sodium phosphate (3).
For peripheral nerve repair (4).
Eyes
Dry eye syndrome is a disorder that affects 5-34% of the world's adult population with reduced quality of life. Artificial or lubricating tears are the most used therapy for treating this condition due to their low side effects profile, which attempt to modify the properties of the tear film. Polyethylene glycol has demonstrated clinical efficacy in the treatment of this condition (5).
Brain
Polyethylene glycol facilitates the neuroprotective effects of magnesium in head injuries (6).
Tumors
For transarterial chemoembolization, Polyethylene glycol is effective and safe for the treatment of liver cancer, as indicated by good tolerability, quality of life and high tumour response (7).
Cosmetics
Many types of PEG are hydrophilic and are used as creams, topical dermatological preparations and in cosmetic products such as surfactants, emulsifiers, detergents, humectants and skin conditioners.
Safety varies from type to type given the structural complexity (8).
