How Long Does Plexaderm Last? (vs Peter Thomas Roth FirmX Tested)

by: Linda Robison / Facial Fitness Specialist

Plexaderm usually lasts 6–8 hours. Peter Thomas Roth FirmX can hold up for 6–10 hours and offers a more flexible finish—especially in heat or on dry skin.

I was curious too, so I tested both to see which one actually holds up best. Both smooth puffiness and wrinkles fast, but their results wear differently.

One delivers a firmer, faster lift. The other gives a softer finish that holds up better throughout the day.

I’ve also tested how Plexaderm holds up against other popular under-eye products like Insta-Tox, No More Baggage, and more. Here’s the full competitor breakdown.

Let’s break it down—especially if you deal with facial movement, dry skin, or hot weather.

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☀️ Summer update:
Warm weather affects how fast-acting serums perform. I tested both during hot, humid days and both actually worked well. 

Once I started to sweat, Plexaderm felt a little tacky on my skin—almost like it was trying to hold everything in place. Peter Thomas Roth FirmX, on the other hand, stayed smooth and dry, even in the heat. Still, both serums managed to visibly smooth out the fine lines and puffiness under my eyes, which honestly surprised me given how humid it was.

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How long does Plexaderm last?

Plexaderm usually lasts 6–8 hours, though some people see results closer to 10. The effect fades faster if you have oily skin, sweat, or make lots of facial expressions, since movement can break down the tightening film.

✔ Pro Tip: For better results consider layering a hydrating eye cream from my best eye wrinkle treatments roundup.

How does Plexaderm work?

Plexaderm works by using sodium silicate, which forms a thin, invisible film on the skin. This film tightens as it dries, temporarily smoothing puffiness and fine lines until it wears off later in the day.

Why do Plexaderm results fade?

Results fade because the sodium silicate film is rigid and can crack with facial movement or break down faster on oily skin—so wear time often tops out around 6–8 hours.

How long does Peter Thomas Roth FirmX last

Peter Thomas Roth FirmX results typically last between 6-10 hours. The flexible film-forming polymers provide a smoother finish than Plexaderm, allowing for more natural facial movement. The added hydration from hyaluronic acid helps maintain results longer, especially on dry skin.

How does Peter Thomas Roth FirmX work?

Peter Thomas Roth FirmX uses film-forming polymers plus hydrating ingredients like hyaluronic acid. This creates a flexible, breathable layer that tightens skin while allowing smoother movement.

Why do Peter Thomas Roth FirmX results fade?

Even though FirmX is more flexible, it’s still a temporary tightening film. Results fade gradually as moisture, facial expressions, or rubbing the skin weaken the polymers.

Which under-eye serum lasts longer: Plexaderm or Peter Thomas Roth?

Plexaderm delivers a quick, dramatic lift, but its rigid film can crack with expression or break down faster on oily skin.

FirmX uses a more flexible, hydrating film that stays smooth longer—especially on dry or mature skin. Both are temporary; in practice, FirmX usually outlasts Plexaderm.

Curious about products better than Plexaderm? I compared those too.

Which is better: Plexaderm or Peter Thomas Roth FirmX?

I couldn’t find a clear head-to-head on wear time, so I tested both.

• Deeper bags / need a fast lift (photos/events): Plexaderm gives the strongest immediate tightening, but can feel dry and may flake with facial movement.
• Mild puffiness / fine lines / dry or sensitive skin / daily wear: PTR FirmX is gentler and more hydrating, and it usually lasts longer through the day with less flaking.

Bottom line: Both are temporary.

• Plexaderm = quick, dramatic fix
• FirmX = smoother look that typically outlasts it

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How to apply under-eye serums for long-lasting results

Here’s how to apply them for optimal effectiveness:

• Start with clean, dry skin. This is essential for best results.
• Do a quick under-eye massage. Gently massaging the area helps reduce fluid buildup and can enhance how well the serum works. (Try this lymphatic drainage technique before applying.)
• Apply a small amount to the under-eye area using your fingertip. Gently pat—don’t rub—until fully absorbed.
• Stay expressionless for 5–10 minutes while the product dries to avoid disrupting the tightening effect.
• Avoid over-applying. A little goes a long way—using too much can lead to visible residue or a cakey look.

General tips:

Helpful pointers for better results and fewer issues.

• Skin Type: Oily skin can cause the product to break down faster, while dry skin may enhance longevity.
• Amount: Apply only a small amount to avoid a cakey finish.
• Touching or Rubbing: Try not to touch or rub your eyes after application, as this can cause the product to wear off more quickly.
• Eyeliner & Concealer: The right products can lift and smooth—but how you apply them matters just as much. Check out these 10 eyeliner tricks for mature eyes—that actually help you look more awake.

What happened when I tested both serums

In my personal trials, both products temporarily reduced puffiness and smoothed fine lines, but I found Plexaderm a bit drying on my sensitive skin, while Peter Thomas Roth FirmX provided a smoother, softer finish.

User feedback generally supports these observations:

Some report that Plexaderm’s formula feels drying and can flake with facial movements, while Peter Thomas Roth FirmX is often praised for its flexibility, smoother feel, and longer-lasting effects.

Note: And yes, I even compared Plexaderm to Preparation-H (yep, the hemorrhoid cream). Here’s the truth about Plexaderm vs Preparation-H hack.

At-a-glance: How the two serums compare

Key ingredients in Plexaderm and Peter Thomas Roth: What does the research say?

Sodium silicate offers a quick tightening effect but may not last long due to its rigidity, while film-forming polymers create a flexible, breathable layer that lasts longer and helps with moisture retention.

Overall, film-forming polymers tend to maintain their effects longer than sodium silicate (Cosmetics and Toiletries, 2024 ; Prequel, 2024 ).

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