See the barrier for yourself.
Water is applied directly to the protected underarm panel. The barrier helps stop moisture passing through to the other side.
Sweat Blocking Undershirt
Sweat Blocking Undershirt
Regular price
£34.95
Regular price
Sale price
£34.95
Taxes included.
Keep underarm sweat off the shirt people see. Soft, breathable modal construction, with three-layer protection engineered into the underarm.
Keeps underarm sweat off your shirt
Silk-soft modal, stays cool, zero elastane
Designed to stay discreet under your shirt
Free UK delivery
Wear it for 30 days. Sweat shows through? Full refund.
Daniel, James & Mark
✓
★★★★★
Daniel
Verified
“Works really well. I'd recommend getting the colour that matches your skin best, but even the black shirts are barely visible under my shirt.”
★★★★★
James
Verified
“I love these undershirts, I've basically filled my whole drawer with them.”
★★★★★
Chris B.
Verified
“Very happy with my Workweek Bundle! I wear one every day for work now and honestly couldn't do without them.”
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See Underform in real life.
Real workdays. Real people. No visible sweat marks.
Shipping information
Shipping information
Enjoy free shipping on all orders. Your order will be processed within 24–48 hours, followed by an estimated shipping time of 3–5 business days.
Once your order has been processed and shipped, you’ll receive a Track & Trace code by email. You can easily track your order at any time through our website.
Plus, every order is covered by our 30-day return guarantee for complete peace of mind.
Guarantee
Guarantee
30-Day Sweat-Proof Guarantee
We stand behind the quality and performance of every Underform shirt. Wear it, wash it and put it to the test for 30 days.
If you’re not happy with the material, the fit, or sweat still shows through your clothing, simply send it back for a full refund. No questions asked.
Another layer. Not another problem.
100% Modal, soft enough to forget you're wearing it, everywhere except where it's built to work harder.
Spun from beechwood cellulose, Modal feels closer to silk than cotton while staying soft and breathable through a long day.
Silk soft hand feel
Absorbs ~50% more moisture than cotton
Holds colour and shape, wash after wash
Moisture stays where it starts.
The protected construction manages moisture inside the underarm area and helps stop it transferring through to your outer shirt.
See the difference.
No visible sweat patches
Wear light colours again
No checking during the day
Invisible under your shirt
Underform, in their words.
Wear it. Wash it. Decide for yourself.
Give Underform a proper try. Wear it through real days and wash it several times. If you are not satisfied within 30 days, you get your money back.
Wear it
Put it through real working days and see how it performs for you.
Wash it
Wash it several times and make it part of your normal routine.
Still not convinced?
Tell us within 30 days and get your money back.
- 30 day money back guarantee
- Free UK delivery
- Not satisfied? Get your money back
Questions people ask before buying
Straight answers, without overselling what it does.
Does it actually stop sweat marks?
Underform is designed to stop sweat transferring through to your outer shirt at the protected underarm area. It doesn't cover the whole shirt or your whole body. It's built specifically for the underarm, where sweat marks are most visible.
I already use antiperspirant. Do I still need this?
Antiperspirant reduces how much you sweat at the skin. Underform doesn't replace that. It's a separate barrier for the sweat that does still reach your outer shirt. Most people use both together, not one instead of the other.
Will an extra layer make me hotter?
The protected underarm area is thicker than a normal T shirt, and you may notice it, especially at first or on a warm day. The rest of the shirt is soft, breathable modal, so the extra weight stays where it's needed rather than across the whole shirt.
What's it made of?
The main body is 100% modal, with no elastane. The protected underarm area uses a separate three layer construction, described earlier on this page.
Which neckline should I choose, Crew or Deep V?
Crew is best if you keep your shirt buttoned up to the collar. Deep V is best if you like to wear one or more buttons open, since it stays hidden with a lower neckline.
How many should I buy?
For everyday wear, most people find two is the minimum to keep one in rotation while the other is being washed. Three covers a working week without relying on same day laundry.
What if it doesn't work for me?
[Answer depends on the final guarantee mechanics. Window length, proof of wear requirement, and refund or exchange terms are not confirmed yet. Do not publish specifics here until Section 13 is finalised.]
How do I wash it?
[Care instructions are not finalised yet. You mentioned moving this into a dropdown on the hero section, so this answer can either link there once built, or repeat the same confirmed instructions once they exist.]