Ingredient review

Benzothiophenyl Dephenethyllatanoprost

INCI: BENZOTHIOPHENYL DEPHENETHYLLATANOPROST

A synthetic prostaglandin analog that may promote eyelash growth but carries risks of irritation and potential side effects.

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In plain English

This is a lab-made ingredient similar to a natural substance called prostaglandin. It is used in eyelash serums to help lashes grow longer and thicker. However, it can cause side effects like eye irritation, darkening of the eyelid skin, and even changes in eye color. It is not well-studied in cosmetics and is considered a potent ingredient that requires careful use.

Quick decision guide

Read the cautions before using

Benzothiophenyl Dephenethyllatanoprost can be useful, but watch for some irritation potential.

Plain-English read

Treat this as a practical screening step before you compare products that contain this ingredient.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Benzothiophenyl Dephenethyllatanoprost.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.

Score terms in plain English

Irritation risk

moderate

Can bother some users, especially with frequent use, damaged skin, or strong companion ingredients.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

emerging

The ingredient may be promising, but claims should be treated more cautiously.

What it is

A synthetic analog of prostaglandin, a hormone-like substance that naturally occurs in the body and influences hair growth cycles.

How it works

It binds to prostaglandin receptors in the hair follicle, extending the anagen (growth) phase of the eyelash cycle, leading to longer, thicker, and darker lashes over time.

Pros

Noticeable lash growth

Many users report visible lengthening and thickening of lashes within weeks of consistent use.

Dual benefit

Can also darken lashes, reducing the need for mascara or tinting.

Cons and cautions

Irritation risk

Common side effects include stinging, redness, and itching around the eyes, which can be uncomfortable.

Potential for permanent changes

There is a risk of irreversible darkening of the iris (eye color change) and darkening of the eyelid skin.

Best for

  • People seeking dramatic eyelash enhancement
  • Those who have tried gentler alternatives without results

Use caution if

  • Individuals with sensitive eyes or contact lens wearers
  • People with a history of eye conditions like glaucoma or uveitis

Usage tips

Apply only to the base of the upper lashes, avoiding the lower lash line and eyes.
Use once daily, preferably at night, and remove any excess with a tissue.
Discontinue use if you experience persistent irritation or vision changes.

Safety summary

Moderate safety concern. Can cause eye irritation, skin darkening, and rare but serious iris color changes. Not recommended for those with eye conditions or sensitive eyes.

Research notes

Limited cosmetic-specific research. Most evidence comes from medical studies on prostaglandin analogs for glaucoma, where lash growth was a side effect. Long-term cosmetic safety data is lacking.

Common label clues

Typical concentration
Very low (typically under 0.03%)
Regulatory status
Not specifically approved by the FDA for cosmetic use; regulated as a cosmetic ingredient in the US, but some analogs are classified as drugs for medical use.
Common uses
Eyelash serums
Environmental note
Synthetic production; no significant environmental concerns reported.

Good to know

  • This ingredient is similar to prescription glaucoma drugs like latanoprost, which were found to have lash growth as a side effect.
  • It is not FDA-approved for cosmetic use, so quality and safety can vary between products.

Common questions

What is Benzothiophenyl Dephenethyllatanoprost in beauty products?

This is a lab-made ingredient similar to a natural substance called prostaglandin. It is used in eyelash serums to help lashes grow longer and thicker. However, it can cause side effects like eye irritation, darkening of the eyelid skin, and even changes in eye color. It is not well-studied in cosmetics and is considered a potent ingredient that requires careful use.

What does Benzothiophenyl Dephenethyllatanoprost do in a beauty product?

It binds to prostaglandin receptors in the hair follicle, extending the anagen (growth) phase of the eyelash cycle, leading to longer, thicker, and darker lashes over time.

Is Benzothiophenyl Dephenethyllatanoprost safe for most people?

Moderate safety concern. Can cause eye irritation, skin darkening, and rare but serious iris color changes. Not recommended for those with eye conditions or sensitive eyes.

Who should be careful with Benzothiophenyl Dephenethyllatanoprost?

Individuals with sensitive eyes or contact lens wearers People with a history of eye conditions like glaucoma or uveitis

Research sources

PubMed - Prostaglandin analogs for eyelash growthOpenFDA - Latanoprost prescribing informationOpenCosmetic Ingredient Review - Safety of prostaglandin analogsOpen

Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.