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Sea Silk Leave-In Hair Serum

Sea Silk Leave-In Hair Serum

For the soft, silky feeling your hair deserves after ocean days.

Regular price $83 NZD · 100mL
Regular price Sale price $83 NZD · 100mL
Sold out
Shipping calculated at checkout.

When your spirit feels full but your hair is left dry, tangled, and rough after a day in the ocean, Sea Silk Leave-On Hair Serum helps bring it back to life.

Created for women who love life in the water, this lightweight Korean-crafted serum helps detangle salt-stiff hair while restoring softness, smoothness, and natural shine.

It seals in lightweight nourishment without heaviness or buildup, leaving your hair soft, luminous, and effortless after every ocean adventure.

— Caitlin, Diver

"I have tried and used so many other products and it just made my hair frizzier. This stuff is legendary!"

Clinically tested

for sensitive skin

One bottle lasts

3-4 months

PETA approved

vegan & cruelty-free

1% for the planet

you give back

How To Use

On damp hair
Warm a small amount between your palms and apply through mid-lengths and ends
to improve smoothness and elasticity.

On dry hair
Use sparingly throughout the day to tame frizz and restore shine after exposure
to salt or chlorine.

Routine
Use daily as your leave-in hair recovery step.

Tip
For optimal recovery, apply immediately after showering once hair is
towel-dried.

Good To Know

Thoughtfully formulated without parabens, artificial colourants, mineral oil, or drying alcohols.

Because no artificial colourants are used, slight variations in the natural hue of the formula may occur over time due to the botanical extracts within. This is completely normal and does not affect product performance or safety.

Dermatologist Tested. Clinically Proven.

Your skin's safety is our priority.

Salt and sun can leave skin vulnerable. That's why our formulas have undergone independent clinical evaluation, to help them recover without adding further stress.

✓ 0.00 Irritation Score
✓ Tested on sensitive & general skin
✓ Verified by SKINMED Clinical Trials Center

Certified by: SKINMED Clinical Trials Center (Korea)

Your Purchase, Our Shared Mission

We believe in giving back to the waters that inspire us. Through our partnership with 1% for the Planet, 1% of every sale is dedicated to protecting our blue playground.

Thank you for joining the movement to restore and preserve our oceans for generations to come.

Shop the Ritual

THE ANTI-FRIZZ OIL VEIL SYSTEM

Smooth & Spread → Weightless Veil → Frizz-Down Finish

A lightweight leave-in serum that combines five botanical oils with a carefully balanced blend of fast- and slow-evaporating emollients.

As the lighter components dissipate, conditioning oils remain as a smooth, non-greasy veil—helping soften water-stressed strands, calm frizz and restore glossy manageability without heaviness or buildup.

STEP 1. SMOOTH & SPREAD

A balanced blend of lightweight conditioning oils and emollients spreads through salt-stiff, rough-feeling strands, helping soften tangles and improve manageability after the water.

STEP 2. WEIGHTLESS VEIL

As the lighter components evaporate, conditioning oils remain on the hair surface to form a smooth, non-greasy veil without heaviness or buildup.

STEP 3. FRIZZ-CONTROL FINISH

The remaining conditioning oils gently coat rough, dry strands, helping reduce frizz and leave ocean- and pool-exposed hair looking smoother, shinier and more polished.

The Ocean Recovery Essentials - Mermaid's Secret

Low-Molecular Marine Plant PDRN
Full-Spectrum Centella Complex
300-Compound Aloe Complex

A proprietary recovery system designed to help care for dry, ocean-exposed strands while supporting softness, hydration, and a more conditioned feel.

Sea Buckthorn Fruit Oil
Argan Oil
Borage Seed Oil
Green Tea Seed Oil
Moringa Seed Oil

Five botanical oils condition rough, dry strands, helping restore softness and enhance healthy-looking shine.

Dimethicone, Isododecane, Dimethiconol, C12-15 Alkyl Benzoate, Fragrance, Hippophae Rhamnoides Fruit Oil, Hexyl Cinnamal, Hydroxycitronellal, Geraniol, Citronellol, Limonene, Argania Spinosa Kernel Oil, Borago Officinalis Seed Oil, Camellia Sinensis Seed Oil, Moringa Oleifera Seed Oil, Tocopherol, Water, 1,2-Hexanediol, Butylene Glycol, Aloe Barbadensis Flower Extract, Aloe Barbadensis Leaf Extract, Aloe Barbadensis Leaf Juice, Centella Asiatica Extract, Melaleuca Alternifolia (Tea Tree) Leaf Extract, Sodium DNA, Asiatic Acid, Asiaticoside, Madecassic Acid, Madecassoside

Scent Profile

Top: Grapefruit, Green Apple, Apricot

Heart: Freesia, Rose, Muguet

Base: Musk

  • Mermaids_Secret_Hair_Serum_with_box

    Circular by Design

  • 100% post-consumer recycled bottle (excluding pump).
    Water-separable labels for easy recycling.
    100% recyclable FSC-certified carton.
    Printed with Soy Ink.

  • The oil immediately detangles. The brush goes through straight away.
  • Leaves my hair feeling incredibly soft, silky, and perfectly defined. Not greasy at all!
  • Leaves my hair soft and frizz free. Makes it look super healthy, like it's 10 years younger!
  • 5 stars: 17 (100%)
  • 4 stars: 0 (0%)
  • 3 stars: 0 (0%)
  • 2 stars: 0 (0%)
  • 1 star: 0 (0%)
G
Giovanna
Instant Detangling

My hair felt amazing. I can't get over how the oil immediately detangles. I literally run it through my hair and the brush goes through straight away.

A
Anonymous
Perfect for my ocean hair!

I never leave my house without this serum! It helps to keep my hair healthy and smooth after freedive in the ocean. Amd it smells so good! I love this product and now it's my must-have! Def recommend it to everyone

J
Justine
Amazing

I absolutely love the hair oil, it has become essential for me now, I can’t rinse my hair with just water anymore without applying the oil afterwards. It leaves my hair feeling incredibly soft, silky, and perfectly defined with such a nice natural curl. Not greasy at all !! My hair also feels much healthier and smoother overall. The oil really feels like silk and the smell is incredible. every time I hug someone, they always compliment it!!
Thank you again for all the mermaid 🫶🏽✨
Honestly, you can truly feel all the love and quality behind your products, and it really makes a difference.

A
Abby
Such a noticeable difference for my dry hair

The Hair Serum was incredible. I’d been going through a really dry period with my hair, and there was a noticeable difference after using it — my hair was so soft. When I was in Caribbean, I really lathered it in, and it helped my hair bounce back so much faster after long days in the salt water.

J
Jane A
Finally able to comb through my hair after ocean days!

Honestly the whole range is incredible, but the hair serum especially blew me away. The smell is to die for, and I was genuinely shocked that I could comb straight through my hair after using it after being in the water. It made such a difference to my ocean hair — I love it.

P
Poppy
Simply the BEST.. better than all the rest

From the bottom of my salty heart, I genuinely adore this serum! I love the whole range but this one is my fave I think! My hair is always a birds nest when I’m finished diving and it’s usually a full scale battle to detangle it and get it hydrated again. After using this though, the knots come out with far less of a battle and my hair doesn’t feel dry and broken when it dries. 11/10 recommend!!

S
Shaina Munro
Obsessed with this Hair Serum

I love how easy it was for me to brush my hair out after a surf! Usually my hair is a rats nest but it combed through like silk!

Hi Shaina, thank you so much for the love! We’ve all been there with the 'rat’s nest' hair after a good surf—it’s the ultimate post-ocean struggle. I’m so happy to hear the Sea Silk Hair Serum lived up to its name and helped you comb through like silk!

M
Mia, Professional Swimmer
A Serum Trusted by Professional Swimmers

I’m a professional swimmer and I’ve never found a serum like the Mermaid’s Secret Hair Serum. It’s incredibly hydrating and makes your hair feel so healthy and luxurious after time in the water. It’s perfect for anyone who spends a lot of time in or around the ocean. I absolutely love it — 10 out of 10. And it smells amazing.

Thank you so much, Mia! It truly means a lot coming from someone who spends so much time in the water. We created Mermaid’s Secret for ocean lovers like you who refuse to compromise healthy hair for life in the sea. So happy the Sea Silk Hair Serum is helping keep your hair hydrated and soft after your swim days

S
Stephanie K.
I have been seriously pleasantly surprised with how much I love this hair serum

I have been seriously pleasantly surprised with how much I love this hair serum. I spend a huge amount of time in the ocean and have really long blonde hair. I have used tonnes of different products on my hair and this serum makes it feel so incredibly silky. This video isn’t after it’s air dried with the serum in which is just incredible . Will be re purchasing!

Thank you so much, Stephanie
Hearing this from someone who spends so much time in the ocean means the world — that silky, lightweight finish is exactly what Sea Silk was designed for.
So grateful you shared your video and experience with us

P
Penny C.
Really Lovely for My Daughter’s Hair

My daughter’s hair can get pretty knotty, and this has honestly made a big difference. It smooths everything out and makes brushing much less of a battle. It feels light in the hair and doesn’t leave that greasy finish some serums do. Smells nice too. Glad we gave it a go.

Thank you so much for your review Penny
We’re so happy to hear it’s made brushing easier and feels light without that greasy finish — that smooth, effortless result is exactly what Sea Silk was created for.
So glad it’s working beautifully for your daughter’s hair

K
Kristina
Beautiful silky hair

I teach freediving in the pool a few times per week and swear by this product. It leaves hair silky and is great post blow dry!

W
Womenssurfingcollective
This hair serum is incredible!

This is honestly the best hair serum I have ever used, and I truly mean that. I have really long hair and it’s a mission keeping it kept and this has made such a big difference, I’m now using it daily. Same with the cleanser, that is now my daily too, it leaves my skin feeling so good and clean I couldn’t be happier!

A
Anonymous
Smooth, Tangle-Free Hair After Every Swim

I use this serum after my swimming sessions, and it makes my hair so smooth and easy to comb through. It also smells so good, so I don’t notice much chlorine in my hair.

E
Esther
Hands down the BEST hair serum I have tried!

Hands down the BEST hair serum I have tried! I use on both wet and dry hair and it leaves my hair soft and frizz free. The serum makes it look and feel super healthy, like it’s suddenly 10 years younger!

Hi Esther,

Thank you so much for the kind words! It means a lot coming from someone who spends so much time in the water.

We designed the serum exactly for moments like that — helping hair recover from salt, sun and ocean days while keeping it soft and healthy.

So happy to hear it’s working beautifully on both wet and dry hair for you.

G
Gemma Lee - Gemmalee Wetsuits
A Game-Changer for Salt-Soaked Hair

From an ocean girly who has tried lots of different products, the sea silk hair serum is a game changer, and has quickly become my favourite. It rehydrates my hair so quickly, de tangles my thick locks and somehow makes my golden sun streaks even more golden! I love it

G
Grace Yun
Feels like mermaid hair

This is honestly the best hair serum I’ve used so far.
The scent is very soft and elegant, not overpowering at all.
It absorbs well and doesn’t feel oily, so my hair never looks greasy after using it.
It actually makes me feel like I have mermaid hair 😊
I also love that it has a pump cap, which makes it easy to carry when traveling.
Another big plus is that it’s gentle enough for me to use with my daughters, so we can all share it together.

Thank you so much, Grace
“Feels like mermaid hair” might be our favourite description yet ✨ We’re so happy you’re loving the soft scent and lightweight finish — that silky shine without greasiness is exactly what Sea Silk was created for.
And we’re glad the pump cap makes it easy to take with you when travelling

C
Caitlin
The best serum ever!

This hair oil is saving my life! Every day I have been in the ocean and using this serum, I have had nice curls back again and I’m so stoked!! I have tried and used so many other products in the past for how much time I spend in the water and it just made my hair frizzier. So this stuff is legendary! I have quite thick curly hair and I don’t even need to use much, but it does wonders!! Highly recommend

Caitlin, this might be the best review ever
Hearing that it’s helping bring your curls back after daily ocean exposure means everything to us — especially for thick, curly hair where frizz can be relentless.
We love that a little goes a long way for you.
Thank you so much for sharing this

FAQs

Shipping

Where do you ship?

We are proud to offer worldwide shipping. We currently ship to the following regions:

  • Oceania: New Zealand & Australia
  • North America: USA & Canada
  • Asia, Europe, and the UK

Can’t find your country at checkout? Please reach out to us via contact form. Our team will be happy to assist with a custom shipping quote for you.

How long will it take to receive my order?

Delivery times depend on your location. Once your order is processed (usually within 1 business day), you can expect the following timeframes.

Please note that deliveries to rural or remote areas will take an additional 2–4 business days.

  • New Zealand: 2–3 business days
  • Australia: 3–10 business days
  • United States, Canada & Asia: 4–10 business days
  • UK & Europe: 5–10 business days

What are your shipping fees?

We offer flat-rate shipping worldwide—including all rural and remote addresses at no extra cost.

  • New Zealand: NZ$5.00
  • Australia: AU$9.90
  • United States, Asia & Canada: US$15.00
  • UK & Europe: US$25.00

Do you offer free shipping?

Yes! We love sharing our products with the world. We offer Free Shipping on all orders over the following amounts:

  • New Zealand: Over NZ$100.00
  • Australia: Over AU$100.00
  • USA, Asia, Canada: Over US$120.00
  • UK & Europe: Over $150

Products & Use

Who are Mermaid’s Secret products designed for?

Our products are designed for those who spend time in the ocean or a pool and want daily recovery for skin and hair after environmental exposure.

Can I use the products every day?

Yes. All products are formulated for daily use as part of a balanced recovery routine.

Do I need to use all three products together?

No. Each product can be used on its own or alongside the skincare and haircare you already use. Together, they simply offer a more complete recovery ritual.

Ingredients & Formulation

Where are your products made?

Our formulas are developed in Korea and manufactured in certified facilities to meet the highest standards of quality and safety.

What is the MerCell™ Repair Complex?

MerCell™ Repair Complex is Mermaid’s Secret’s signature recovery blend designed for skin and hair exposed to salt, sun, and wind. It combines Marine Plant PDRN, Centella (Cica), and Triple Aloe Complex to help calm heat-stressed skin, support the barrier, and restore softness and hydration after ocean exposure.

Is Mermaid’s Secret suitable for sensitive skin?

Yes. Mermaid's Secret is designed with sensitive, ocean-exposed skin in mind. Our formulas are built around calming ingredients — including Centella (Cica) and Triple Aloe Complex — to soothe and restore skin after salt, sun, and wind exposure.

All products have been independently tested and clinically evaluated for skin irritation, and confirmed non-irritating — even for sensitive skin.

  • Primary Dermal Irritation Test – Non-irritating
  • Primary Dermal Irritation Test on Sensitive Skin – Non-irritating

Sustainability & Packaging

What kind of packaging do you use?

Our packaging uses 50–100% post-consumer recycled plastic, FSC-certified paper, soy-based inks, and water-separable labels to support cleaner recycling streams

Are you affiliated with any environmental initiatives

Yes. Mermaid’s Secret is a proud member of 1% for the Planet, contributing to environmental causes through our sales.

Orders & Support

How do I apply a promo code to my order?

Enter your promo code in the “Discount” box at checkout. Only one promo code can be applied per order. Promo codes cannot be added after an order is placed and have no cash value.

How do I check my order status?

Once your order ships, you will receive a shipping confirmation email with a tracking number. Please allow up to 24 hours for tracking updates to appear.

Who can I contact if I need help with my order?

For any questions regarding your order, please contact us via our Contact Us Form or directly at hello@mermaidssecret.com. We will response within 1 business day.

How do I check my order status?

Once your order ships, you’ll receive a confirmation email with tracking details.

If you have an account, you can also view your order status by logging in.

I didn’t receive my order confirmation email — what should I do?

Please check your spam or promotions folder first.

If you still can’t find it, contact us at hello@mermaidssecret.com and we’ll help you right away.