Helly Hansen LIFA Merino Lightweight Half Zip Baselayer review

This lightweight baselayer for cooler conditions with the warmth and versatility of merino wool

T3 Platinum Award
Helly Hansen LIFA Merino Lightweight Half Zip Baselayer review
(Image credit: Matthew Jones)
T3 Verdict

At first glance, this Helly Hansen baselayer appears to be a standard merino top. But it’s lined with fast-wicking LIFA fibres for superior moisture management, while also delivering lightweight warmth. It also gets top marks when it comes to fit and features, making it a great multi-activity layer for active use, from hiking and climbing to skiing and snowboarding.

Reasons to buy
  • +

    Warm and wicks moisture fast

  • +

    Soft and comfortable

  • +


Reasons to avoid
  • -

    No thumb loops

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The LIFA Merino Lightweight Half Zip Baselayer is Helly Hansen's latest offering, and I've been putting it through its paces to see how it compares to the best base layers on the market.

Norwegian brand Helly Hansen is largely responsible for the development of the modern performance sports baselayer. In the early 1970s, their classic long-sleeved LIFA tops appeared, with the classic striped branding down each arm.

Made from fast-wicking synthetic fabric – polypropylene yarn, to be precise – they kept wearers warm, dry and comfortable whether they were skiing, hiking or climbing. They soon became pretty much standard wear, supplanting silk and wool underwear as the next-to-skin layers of choice for most active users.

These early synthetics only had one real drawback – their pong. After a while, they tended to pick up and retain body odour that even multiple washes couldn’t shift, giving rise to the term ‘smelly Helly’.Fortunately, it’s a problem that the brand has tackled.

The current range of LIFA merino layers has no such odour issues, using a combination of synthetic LIFA fibres and natural merino wool in an innovative two-layer construction to deliver the hybrid benefits of the different fabrics.

Helly Hansen LIFA Merino Lightweight Half Zip Baselayer review


  • RRP: £80 (UK) / $100 (US) 
  • Weight: 235g/8.3oz (160gsm)
  • Materials used: Shell: 70% Merino Wool, inner 30% Polypropylene
  • Sizes: Men’s S-XXL, Women’s XS-XL

Design and features

Helly Hansen LIFA Merino Lightweight Half Zip Baselayer

(Image credit: Matthew Jones)

At first glance, this looks like a fairly standard lightweight 160gsm merino long-sleeved top. Closer inspection reveals plenty of well-considered design details developed with comfort and performance in mind, though. The neck zip is backed with a soft flap to stop the cold metal zipper teeth from coming into contact with the skin, and there’s a chin guard at the top, too, to prevent irritation.

A raised collar wards off chills that might creep down your spine and the inside of the collar is lined for comfort, too. Critical seams are flatlocked to minimise chafing and reduce bulk, including those along the shoulders and underneath the arms.

Then there’s the trademark Helly baselayer fit, which ensures ample length in the arms and torso for full coverage, with a close cut that creates a trim silhouette without feeling skin-tight or restrictive.

But it’s when you turn this baselayer inside out that it really starts to stand out. It is lined with a fine mesh of interlocking synthetic LIFA fibres. These sit next to the skin to provide optimum wicking performance, pulling moisture away from the skin to keep you dry. Meanwhile, that lightweight merino wool face traps warmth and regulates temperature. It’s a two-layer construction that works even better than the zoned or body-mapped panels of different fabrics that other hybrid layers tend to adopt.

Any niggles? There is only one, really, which is that the sleeves lack thumb loops. This is a matter of personal preference, but it’s a feature that many users appreciate, helping to ensure sleeves are pulled in under gloves and jacket cuffs. On the other hand, the sleeves are fairly long and not at all baggy, so it’s not a major issue.

Performance and comfort

Helly Hansen LIFA Merino Lightweight Half Zip Baselayer

(Image credit: Helly Hansen)

Helly’s patented LIFA fibres are made from polypropylene, which is basically the king of synthetic fibres when it comes to outright wicking performance. In the LIFA Merino baselayer, these are placed on the inner face of the garment, directly against the skin, so they do a great job of moisture management to keep you dry, even when working up a sweat.

As a lightweight 160gsm layer, it provides limited warmth. However, for users who run hot or who will be staying active, it’s perfect, even for winter wear – though if you feel the cold, you might want a heavier option (Helly also do a LIFA Merino midweight baselayer with this in mind). However, we used it for winter hillwalking and mountaineering in snow and ice in Snowdonia, North Wales, with just a Gore-Tex Pro shell over the top, and stayed very comfortable all day long, as ambient temperatures stayed at around -2°C throughout the day.

It's a comfortable base layer with a great fit. It keeps the neck, wrists and lower back warm, even during dynamic activity.

We also wore it for three days straight to see whether it started to smell. We’re happy to report that it stayed impressively fresh – an opinion seconded by an initially sceptical climbing partner!

With lightweight Merino, shape retention and durability are often issues. It seems that the synthetic lining of this layer helps in both those respects, though, since after several wears and washes, it still looked and felt great, with no obvious holes, pilling or bobbling.


Helly’s LIFA Merino layers deliver impressive next-to-skin performance, keeping you warm, dry and comfortable during high-output activities. You can’t ask for more than that, and as such, we’d recommend them for almost all mountain pursuits. They wick better than pure merino too, and seem to be more durable, keeping their shape better even after washing. Nor has odour been a problem. 

Also consider

Arc'tryx's Rho Hybrid is a premium quality base layer with great next-to-skin comfort, optimal level of insulation and good moisture wicking performance. It is soft and comfortable to wear, thanks to a great full-coverage fit. That hybrid combination of synthetic fibres and natural merino woolis a winner. Read Matthew's full Arc’teryx Rho Hybrid Half Zip Baselayer review.

Matthew Jones

An outdoors writer and editor, Matt Jones has been testing kit in the field for nearly a decade. Having worked for both the Ramblers and the Scouts, he knows one or two things about walking and camping, and loves all things adventure, particularly long-distance backpacking, wild camping and climbing mountains – especially in Wales. He’s based in Snowdonia and last year thru-hiked the Cambrian Way, which runs for 298 miles from Cardiff to Conwy, with a total ascent of 73,700ft (that’s nearly 2½ times the height of Everest). Follow Matt on Insta and Twitter at @mattymountains