Smooth, Soft, and Soothing: More Merino Wool Myths, Busted

The skin is our biggest organ. No wonder there’s lots of differing opinions and perceptions about what we wear on it. And in some times, and places, wool has carried a reputation for being scratchy, itchy, and even the cause of allergies.

What if we told you that the case against wool wasn’t quite so black and white, and in some ways, lands on the opposite side of the fence? We’re going to fact-check four wool myths (round two of our Merino myth-busting), and find out why we choose this fantastic natural fiber for our socks — perfect for comfortable wear, day in and day out.

Myth: Merino Wool Is Itchy

Let’s start with the concept of itching in general. Humans evolved an alert system to let us know about ticks, bugs, and other disease-carrying objects and substances on our skin. A set of neurological signals cascade to the brain after that alert is triggered, and, you guessed it, our reaction is to itch. That response is just a temporary solution, as the physical act of itching then adds inflammation to the itch site. And on the cycle goes 

Our itch reaction served us well in the wild, and still does when something irritating lands on our skin. And when you think about that feedback cycle, it’s no wonder we’re not into wearing itchy things. The question remains: Can wool socks irritate skin?

To find out, let’s break down what the itch system is on the lookout for: thermal, chemical, and mechanical stimuli. Wool is temperate regulating, actively creating a balanced temperature and humidity climate between fiber and skin. So temperature (aka thermal stimuli) isn’t the problem.

As far as chemical concerns, wool is made up of keratin, the same protein as human hair, and as we’ll see below (spoiler alert!), it’s not an allergen in most cases. So that leaves “mechanical,” which in practical terms is something solid interacting with something else solid.

What is going on here? Do Merino Wool socks itch, or not? What we’ll look into next is how the diameter of the fiber we’re talking about comes into play.

Myth: Merino Wool Is Prickly

Since wool was recognized for its warmth, versatility, and ability to function in damp climates hundreds of years ago, this natural fiber has become one of the top fibers used for cold-weather clothing. There’s no way to pinpoint when concern over skin reaction to wool socks started, but our guess would be that at some point, chunky, heavy-gauge sweaters and knit-wear dominated the public perception of what wool feels like.

About that “chunky” description. In the fiber business, wool is measured in units called “microns” — for example, human hair is around 50 microns.

In this case, what’s true is that wool can be itchy, and prickly, in its coarser forms. Rough wool, like the type used in heavy garments, is around 35-40 microns. That might seem “thin” since that’s slimmer than human hair, but those fibers “mechanically” rubbing against your skin are both thick and stiff enough to send out that alert signal.

Skin reactions to wool socks reduce dramatically when we get into the ultra or superfine Merino Wool used in Darn Tough socks: around 17-19 microns in diameter. Compared to traditional wool, Merino’s increased “crimp” (the natural “wave” in the fiber) goes beyond boosting insulation and thermal regulation — it equals more elasticity and resilience, letting Merino drape and move easily over the skin, while restraining any loose threads from popping out.

Imagine the face of a rough-knit sweater: it’s likely to be chunky, with stray hairs jutting out at all angles. We love wool of course, but we’re not likely to wear that sort of piece without something underneath. Take a look at your Darn Tough socks in comparison. The surface is smooth, supple, and the knit is tight.

The result is that Merino doesn’t itch. It’s so soft that it simply bends when it comes in contact with your skin, instead of “mechanically” pricking or itching. And the truth, we’ll come to find out, is even more illuminating: “itch” can happen with any fiber, wool, cotton, synthetic, or otherwise.

Myth: Merino Wool Causes Allergies

By now you might be wondering, is there such a thing as a wool sock allergy? It’s a valid concern, given the fact that for decades wool was pointed to as a potential trigger for allergic reactions. Lanolin, the protective, waxy layer covering each strand of sheep hair was believed to be the main source of discomfort.

What’s become clear is that wool allergies simply aren’t an issue for most folks. A look at people with high risk for allergies showed that less than 2% of them reacted to lanolin. Recent studies of people who suffer from allergies, and a larger review of existing evidence for wool allergies have debunked this myth, proving that few people actually react from wool.

Then what’s going here? Are we onto an X-Files cold case? Nope, no flying saucers here. These studies turned up the same simple and common perpetrator. Whether its acrylic, nylon, or wool, stiff and coarse (or thicker-micron, if you’re getting into the technical stuff by this point) fibers will light up our skin’s alert system.

So it’s right back to what we were talking about before. Step into the world of Merino Wool, and let that fine-micron smoothness ease this misconception.

Myth: Wool Isn't Soft

Speaking of softness, we can’t let this one slide. Hand-feel is a subjective thing, and with our skin being the largest organ in our bodies, everyone is free to evaluate this on their own. 

What we can probably agree on is that supple is preferred to harsh when it comes to garments, like socks, that you’ll be wearing next to skin. That’s why we choose Merino for our socks.

With its ultra-fine diameter, flexibility, and natural rebound, Merino goes beyond the functional performance of keeping us warm in the cold and cool in the heat, to providing a sleek, and, we think, soft-wearing solution for socks.

Fact: Merino Wool Can Soothe the Skin

What if wool wasn’t just “not itchy,” but could actively soothe skin? Recent studies have turned up evidence to support this.

Eczema, or “Atopic Dermatitis,” is an allergic condition where the skin becomes dry, resulting in painful cracking, bacterial infection, redness, and itching. Recent studies on people suffering from eczema show that Merino clothing isn’t just tolerated: in some cases, symptoms are reduced.

How is that possible? Wool’s amazing natural structure allows it to absorb and release twice as much moisture vapor as cotton, and thirty times as much as polyester. Merino Wool’s ability to manage moisture and temperature, combined with inherent breathability, helps regulate body temperature, preventing the skin from becoming clammy and reducing risk of bacterial infection.

This is why we love Merino — when worn next to the skin, it functions as a dynamic buffer in the micro-climate between fabric and skin, smoothing out humidity and temperature, providing a more comfortable environment. Both studies showed a downward trend in eczema symptoms while wearing superfine Merino Wool garments next to the skin, something folks with this condition can celebrate.

Beyond Merino: How You Build It Makes a Difference

Now that we’ve debunked more myths about Merino, and learned some about why we use this amazing natural fiber along the way, there’s a little bit more to it. Itchy, prickly, even rash-inducing wear could still take place when you’re in Merino.

Stick a seam in a high-wear, high-rub area, or construct your socks so they don’t fit snug, and you’ll likely end up with hot spots and maybe even blisters. That’s an issue Owen Rachampbell, Darn Tough Product Line Manager, and avid hiker, talks about preventing here.

As you might guess, just like busting these Merino myths, we take these concerns seriously. That’s why we’ve got features like a Seamless Toe for protecting your digits, Flex Zones to reduce bunching, and a Performance Fit that stays put all day long, no matter how much vertical, or how many office meetings, you’re clocking. We love Merino, and we’ve designed our socks to maximize its potential.

The Big Reveal

There you have it. Merino isn’t itchy, prickly, an allergen, and can in fact be soothing to the skin as well as just plain soft. Surprised?

When you see a sheep in the wild, shredding around the hills hanging on by just it’s hoofs, protected by its hair from the dampest, coldest climates, it makes sense to think wool might be, well a bit rough. We’re happy you stuck in there to find out how Merino Wool flips that perspective on its head, one of the reasons we keep loving and using this renewable natural fiber.