What is E1521?

Complete guide to understanding polyethylene glycol in your food

The Quick Answer

E1521 is polyethylene glycol (PEG), a polymer used primarily in food supplements and pharmaceutical capsules.

It’s used to stabilize textures, bind moisture, and carry colors and flavors in food products.

It’s a synthetic substance derived from petroleum that has been used in food and medicine for decades.

What Exactly Is It?

E1521 is made from ethylene oxide polymers derived from petroleum.

The name comes from its structure: multiple ethylene glycol units linked together to form a long polymer chain—hence “poly” (many) “ethylene” (the repeating unit) “glycol” (a type of alcohol).

In technical terms, it’s expressed chemically as H−(O−CH₂−CH₂)ₙ−OH, where “n” can be many hundreds or thousands of units.

Depending on molecular weight, E1521 can be a clear liquid (lighter PEG) or a white waxy solid (heavier PEG like PEG 3000, PEG 4000, or PEG 6000).

It’s highly stable, resistant to enzymes and microorganisms, and soluble in water and many organic solvents.

Where You’ll Find It

E1521 appears most commonly in:

• Food supplement capsules and tablets
• Candy and sweets (prevents sticking)
• Baked goods and confectionery
• Beverages (carries flavor and color)
• Pharmaceutical coatings
• Electronic cigarette liquid (e-liquid)

In the EU, E1521 is primarily authorized as an additive in food supplements and pharmaceuticals.

Most of your dietary exposure comes from taking supplements or medications, not regular food.

Why Do Food Companies Use It?

E1521 serves multiple functions:

In food supplements: Acts as a binder and coating agent in tablets and capsules, improving shelf life and making the product easier to swallow.

In beverages and confectionery: Acts as a humectant (moisture binder) and carrier for flavors and colors, keeping products moist and preventing them from clumping together.

As an anti-foaming agent: Prevents unwanted foam formation in various food products.

Without E1521, many supplement capsules would be difficult to manufacture, and confectionery products would stick together and lose their texture.

So pharmaceutical and food manufacturers use it for practical, quality-control, and shelf-life reasons.

Is It Safe?

E1521 is generally considered safe by regulatory bodies worldwide.

The FDA has approved it, the EFSA (European Food Safety Authority) permits its use in the EU, and JECFA (the joint FAO/WHO expert committee) has established an Acceptable Daily Intake (ADI).

The group ADI for polyethylene glycols (PEG 300-4000) is 5 mg/kg of body weight per day according to the European SCF, and 10 mg/kg per day according to JECFA.

For a 70 kg adult, this means up to 350-700 mg daily is considered safe.

Actual exposure from food and supplements is estimated at 3.5-6.1 mg/kg body weight per day at typical consumption levels—well below safety thresholds.

PEG is rapidly metabolized and excreted; it does not accumulate in the body.

Natural vs Synthetic Version

E1521 is always synthetic—there is no natural version.

It’s manufactured in laboratories through chemical synthesis of petroleum-derived ethylene oxide.

There is no naturally occurring equivalent in food or nature.

This is distinct from some other food additives that can be extracted from natural sources.

However, synthetic doesn’t mean unsafe—it’s been used in pharmaceuticals for over 60 years with a strong safety record.

Natural Alternatives

Want to avoid E1521?

In food supplements, companies sometimes use:

• Gelatin capsules: Traditional alternative (but not vegetarian)

• Vegetable-based capsules (cellulose): Plant-derived coating (more expensive)

• Gum arabic or gum arabic-based binders: Natural stabilizers

• Xanthan gum or locust bean gum: Plant-based thickeners

These alternatives work but are often more expensive and less stable.

So synthetic PEG remains the industry standard for cost and consistency reasons.

The Bottom Line

E1521 is a long-chain synthetic polymer used primarily in supplements and pharmaceuticals.

It’s not found in large quantities in everyday food—mainly in capsule coatings, candy, and beverages.

Regulatory agencies worldwide—FDA, EFSA, WHO—consider it safe at approved levels, and actual human exposure is below safe limits.

It’s been used in medicine for decades without serious safety concerns in the general population.

However, if you prefer to avoid synthetic additives, read supplement labels carefully and look for brands using vegetable capsules instead of PEG coatings.

You have the right to know what’s in your food and supplements—and to make informed choices.