What Is Glycerin?

Glycerin, also called glycerol, is a sugar alcohol and carbohydrate naturally found in certain fruits and foods. It’s also a component of triglycerides, the fat stored in your body. In its pure form, glycerin is a clear, thick, sweet-tasting liquid.

Glycerin is commonly used in skincare, food, and medicine. It can be naturally derived from fermented plant sugars or manufactured through hydrolysis from vegetable oils, animal fats, or synthetic petroleum sources.

Common Uses of Glycerin

Glycerin plays a functional role in various products:

  • Food and supplements: Acts as a sweetener, thickener, and preservative

  • Skincare and cosmetics: Provides moisture retention and softening effects

  • Eye drops and medications: Lubricates and protects sensitive tissues

  • Laxatives: Works as a suppository to relieve constipation

Its humectant and emollient properties make it especially valuable in moisturizing products, where it draws water into tissues and forms a protective layer to prevent water loss.

Health Benefits of Glycerin

1. Skin Hydration and Repair

Glycerin is well-known for its ability to:

  • Pull moisture into the skin’s outer layer

  • Soften and smooth dry or damaged skin

  • Strengthen the skin barrier and aid in wound healing

Topical application can prevent dryness and help manage eczema and other skin conditions.

2. Eye Moisture

Glycerin-based eye drops are effective in:

  • Reducing dry eye symptoms

  • Lubricating and hydrating the eye surface

  • Supporting eye comfort, especially in dry environments

3. Digestive Relief

Used rectally, glycerin acts as a:

  • Mild stimulant and osmotic laxative

  • Moisture-attracting agent that softens stool

  • Promoter of intestinal contractions for easier bowel movements

4. Athletic Endurance Support

Early research suggests that glycerin ingestion may:

  • Improve water retention

  • Delay dehydration during intense exercise

  • Enhance endurance in athletes

In one study, soccer players consuming glycerin showed better performance, though some also experienced minor weight gain due to fluid retention.

Safety and Potential Side Effects

Generally Safe With Moderate Use

Glycerin is considered safe for topical and internal use, according to the FDA (GRAS status). Most people tolerate it well at standard doses:

  • Up to 30 mL orally

  • Applied as directed on the skin

Possible Side Effects

  • Topical: Skin irritation or allergic rash (rare)

  • Ocular: Burning or stinging sensation

  • Oral (large doses): Dehydration symptoms like nausea, vomiting, headache, dizziness, or diarrhea

Toxicity may occur if doses exceed 1,428 mg/kg of body weight.

Choosing the Right Glycerin Product

Options Available

  • Skincare: Lotions, creams, soaps

  • Medical: Eye drops, rectal suppositories

  • Oral: Found in foods and energy drinks

  • Pure glycerin: Can be used directly for skin hydration

Ingredient Origin

  • Vegetable-based glycerin is preferred for natural or vegan users

  • Synthetic or animal-sourced glycerin is also available, often more common in industrial applications

Always read product labels and opt for trusted manufacturers, especially if you prefer plant-based or non-synthetic ingredients.

Summary

Glycerin is a versatile compound that provides deep hydration, helps treat constipation, and improves eye comfort. Whether applied to the skin, taken internally, or used in medical treatments, glycerin’s humectant properties make it highly beneficial across a range of applications.

Though generally safe, it’s essential to use glycerin products appropriately and consult a healthcare provider if you experience adverse reactions or have specific health concerns.