Comparing Tria's 4X Vs Silk'n's SensEpil Permanent Hair Removal

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The Tria 4X and the Silk'n SensEpil are two machines you can use for permanent hair removal. Learn about the main differences between their technology, life, results, pain, and cost. The latest Tria 4X (henceforth designated as T4X) and Silk'n SensEpil (from hereon referred to as SE) are the models that we'll be measuring against each other.

Technology and Areas of Use

T4X: A diode laser that's FDA cleared to be used on the legs, arms, bikini line, underarms, feet, stomach, back, chest, hands, and women's facial hair from the cheek line down.

SE: Uses IPL (intense pulsed light) technology for home hair removal, FDA cleared for permanent hair reduction that requires disposable lamp cartridges. The device is designed to be used on the body (excluding genitals) but can be used on the face from the cheek line down.

Although they can be used on the face, know that laser or IPL may stimulate hidden facial hair to grow in women.

Power and Settings

T4X: Cordless, hand-held rechargeable device with five adjustable power settings.

SE: Corded, hand-held device with five adjustable power settings.


T4X: Those with light to medium skin tones (white, ivory, beige, and light brown) and dark hair. White, gray, blonde, or red hair will not benefit from using the system.

SE: The best candidates also have light to medium skin tones and dark hair. Shades of brown hair might also respond to the system, but typically require more treatments. Red hair could possibly benefit from treatments. White, gray and blonde hair don't usually respond although the company does mention that some have noted results after multiple treatments.

The devices will target melanin (or color), so dark hair benefits the most because it has the most color to absorb the heat to impair the hair follicle. However, this also means that people with darker skin tones can't safely use either system because the melanin in the skin can also be attacked resulting in burns, scars, or blistering.


T4X: Has a built-in skin sensor that checks skin tone, and it'll unlock for use if it's within the right range.

SE: Has a built-in skin sensor that will pulse light or 'zap' if the skin is within a safe tone range. (This built-in skin sensor feature in only on the Silk'n SensEpil, not the original Silk'n.)

Recommended Treatment Times

T4X: Every week for three months, or until you're satisfied with the results.

SE: A complete treatment time is considered anywhere between 18-24 months. Every two weeks for the first four sessions and to treat again when hair starts growing back or every four weeks. You go over the area once with no overlapping.


T4X: The feeling of using this Tria is often compared to a rubber band snap with some heat on top of it. I've personally used the original Tria with three power settings on the highest option for most of my bikini line. It didn't really hurt, but I could definitely feel the snap. As I got deeper into my bikini line there was more discomfort and I did turn the power down a notch. The latest model now has five power settings.

SE: It's been a mild sensation of warmth and tingling. I used the Silk'n SensEpil on the highest of the five settings on my legs and underarms. It didn't hurt at all on my legs and wasn't uncomfortable, not even a little. My underarms didn't hurt per se, but every now and then I would feel a snap.

Everyone has their own tolerance to pain and discomfort. You might feel more pain if you have sensitive skin or very dark or thick hair. Not shaving your hair down fully right before treatments will make for more unnecessary discomfort. The first treatment usually hurts the most, and it's important to remember that using the highest setting on either device will also produce more heat, so is more likely to give you pain or discomfort.


T4X: The round head of the Tria is fairly small—the diameter is a little under a 1/2". As you can imagine, each use can take a decent amount of time depending on the area you're working on.

SE: The rectangular head of the system is very large (about 1" x 1 1/4") so treatments are very fast. Both of my entire legs were done in half an hour and both underarms in less than five minutes.

Ease of Use

T4X: It fits in the hand nicely, and it's very easy to operate. The cordless feature does allow you to twist and turn the device as easily as you want. However, if you're in the middle of a treatment and it dies, you have to stop and wait for it to recharge—and remember exactly where you left off.

SE: Cradles in the hand and is very easy to use. It's not cordless, but that never seemed to be a hassle or a problem. In fact, using it as long as you need without having to re-charge it is great. Temporary impressions from the head—lasting about 30 seconds—are made into the skin to let you know exactly where you've hit, so you can easily go to the next section without overlapping. You have to be careful to follow these lines exactly or you could end up missing a spot.

Life and Cost

T4X: Has a retail price of $449 (compare prices on Amazon). Tria Beauty Company points out that it's capable of delivering up to 90,000 pulses. When it runs out, you'll need to buy another device.

SE: The suggested retail price is $299, but Silk'n no longer sells the SensEpil. They do, however, still sell the cartridges.


T4X: The company claims it "delivers up to 70% hair count reduction in just two treatments."

SE: The device is FDA cleared for permanent hair reduction. According to the Silk'n clinical study of 150 females using the hair removal system, these were the average hair reduction results after 6 months: "41% in the underarms, 54% on the legs, 43% in the bikini area and 52% on the arms."

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