The Leave-In Hair Treatment

Clean Science. Powered by TFC8®.

Healthier hair in a bottle, The Leave-In Hair Treatment replenishes, smooths, and softens strands, boosts shine and vibrancy, and strengthens your hair while helping to reduce breakage and support natural hair growth.

Formulated for all hair types, this game-changing serum is the ideal antidote for all your hair concerns. From dehydration, shedding, and frizz to breakage, split ends, and damage from over-styling or color-processing, this restorative, antioxidant-packed concentrate instantly improves your hair’s look and feel while promoting its long-term health. Experience haircare redefined. Backed by 30 years of cutting-edge science. Powered by TFC8®.

Housed in a 100% recyclable tube made from sustainable sugar cane and 100% recyclable cap. Carton and leaflet are FSC-certified and recyclable.


PRODUCT DETAILS | How To Use | Ingredients | Trials/Results

The Leave-In Hair Treatment

Clean Science. Powered by TFC8®.

Healthier hair in a bottle, The Leave-In Hair Treatment replenishes, smooths, and softens strands, boosts shine and vibrancy, and strengthens your hair while helping to reduce breakage and support natural hair growth.

Formulated for all hair types, this game-changing serum is the ideal antidote for all your hair concerns. From dehydration, shedding, and frizz to breakage, split ends, and damage from over-styling or color-processing, this restorative, antioxidant-packed concentrate instantly improves your hair’s look and feel while promoting its long-term health. Experience haircare redefined. Backed by 30 years of cutting-edge science. Powered by TFC8®.

Housed in a 100% recyclable tube made from sustainable sugar cane and 100% recyclable cap. Carton and leaflet are FSC-certified and recyclable.


PRODUCT DETAILS | How To Use | Ingredients | Trials/Results

Donate 5% of your order value to a charity of your choice. Learn More

€42.00
+420 Loyalty Points
50ml
-
+
Back

Set Up Replenish

Buy five and get the sixth free, plus these benefits

Replenish Benefits

  • Enjoy a welcome gift on sign-up and receive every 6th auto-replenish product for FREE
  • Earn Loyalty Points on your Replenish orders, to be redeemed on site
  • Customize your experience. Our tools will help calculate your ideal frequency - receive what you need, when you need it - no more or no less
The Leave-In Hair Treatment
The Leave-In Hair Treatment
Our recommended frequency for you is below, but you can change as required using the dropdown

Choose your free gift

We'd like to offer you a free welcome gift with your new Replenish order.

  • FREE delivery worldwide
  • 30 day returns
  • Earn 420 loyalty points

Pay Later with Klarna.

Pay installments of
Why Choose The Leave-In Hair Treatment

The Leave-In Hair Treatment

KEY BENEFITS
  • Replenishes and smooths strands, boosts shine, tames frizz, and strengthens hair without weighing it down.
  • Helps to support natural hair growth while preventing shedding and breakage.
  • Helps to reverse brittle or weakened hair - renewing strands, improving hair thickness, and noticeably reducing the appearance of split ends.
  • Ultra-nourishing and hydrating seals in nutrients and helps the hair retain moisture for silky locks with a healthy bounce.
  • Softens and detangles hair for easier combing and reduced breakage.
  • Combats damage caused by daily styling, color processing, chemical treatments, and environmental aggressors - for stronger, shinier, more resilient hair.
  • Ingredients that support improved scalp health with soothing, fortifying, and anti-inflammatory properties.
VISIBLE RESULTS
  • 100% agree hair looks and feels healthier after use
  • 90% agree The Leave-In Hair Treatment helps repair hair from heat
  • 97% agree hair feels easier to manage/style after use
  • See clinical and user trials.
ABOUT
  • Ultra-nourishing, and fast-absorbing. Residue-free and does not weigh down hair.
  • Formulated without irritants, allergens, silicones, parabens, or sulfates. Fragrance-free.
  • Suitable for all hair types. Vegan.
  • See ingredients.

How To Apply

Apply a small amount to clean, dry or towel-dried hair. Using fingertips or The Neem Comb, work from the scalp or midlength to the end of hair, focusing on areas of need. Allow hair to dry naturally, or blow dry for an enhanced finish.

  • Use 2 to 3 times per week as needed.
  • For best results, use in conjunction with the Augustinus Bader haircare system: The Shampoo, The Conditioner, The Scalp Treatment, and The Hair Oil.
  • Suitable for all hair types.
Duration: 41s
The Evidence Is In

Clinically Proven Results

dive into the evidence

User Proven Results

The Leave in Hair Treatment

The Leave-In Hair Treatment

99%

agree hair feels and looks healthier after use.

94%

agree hair breakage is decreased.

97%

agree their hair looks smoother.

all results for this product

The Leave-In Hair Treatment

97%

agree hair feels easier to manage/style after use.

93%

agree frizz is reduced/tamed.

97%

agree The Leave-In Hair Treatment makes hair shinier.

all results for this product

The Leave-In Hair Treatmentt

95%

agree The Leave-In Hair Treatment detangles hair.

96%

agree The Leave-In Hair Treatment does not leave residue on hair.

100%

agree overall hair quality is improved.

all results for this product

The Leave-In Hair Treatment

96%

agree The Leave-In Hair Treatment helps their hair color appear more vibrant.

99%

agree that hair looks and feels renewed and restored after use.

95%

agree The Leave-In Hair Treatment helps reduce styling time.

all results for this product

The Beauty of TFC8®

Our proven results are powered by Professor Bader's TFC8®, or Trigger Factor Complex - an exclusive patented technology comprised of over 40 ingredients and inspired by over 30 years of research, innovation and clinical study.

1

TFC8® technology guides key nutrients and powerful natural ingredients to the scalp, follicles, and hair, creating and supporting an optimal environment for cellular renewal.

2

TFC8® turns potent base formulations into smarter, adaptive haircare capable of addressing individualized concerns - such as weak, thinning, or brittle hair, dehydration, shedding and breakage, split ends, frizz, and damage from over-styling, coloring, or external stressors.

3

TFC8® nourishes and protects, training the hair for the long-term. Resulting hair looks and feels healthier, stronger, fuller, and more vibrant.

How TFC8® technology works
clean & high quality

Key Ingredients

Augustinus Bader haircare is formulated with sustainably-sourced, high potency botanicals and bio-engineered clean actives where possible, to reduce environmental impact.

The Leave-In Treatment

Powered by our patented TFC8® technology and formulated with potent hair superfoods and anti-oxidants including Neem Extract, Shikakai Extract, and Rambutan Extract to fortify and thicken tresses while actively protecting strands against daily damage.

See all ingredients | Free From List
The Leave in Treatment Ingredients
Tara Fruit Extract & Sunflower Seed Oil Blend

A potent plant-based duo. Naturally protects hair against stressors including heat, pollution, and UV. Repairs chemically treated hair, prevents color fading, and helps restore overall resilience and vitality.

The Leave in Treatment Ingredients
Rambutan Fruit Extract

A fruit-derived powerhouse. Revitalizes and protects the scalp and hair follicle against pollution. Hydrates the scalp and delivers free radical protection, for stronger, shinier hair.

The Leave in Treatment Ingredients
Shikakai Extract

A beautifying botanical derived from an herb native to Asia. Naturally softens, detangles and refreshes hair, while keeping the scalp optimally hydrated, preventing flakiness, fortifying strands, and supporting growth.

The Leave in Treatment Ingredients
Neem Extract

A powerful medicinal herb used for generations to address hair loss. Potent antibacterial, antifungal and anti-inflammatory properties help optimize scalp health while strengthening the hair follicles and encouraging growth.

The Leave in Treatment Ingredients
Biotin

A vitamin essential to the body’s metabolic processes. Known to help thicken hair, stimulate growth, and prevent shedding.

The Leave in Treatment Ingredients
Argan Oil

A nourishing antioxidant pressed from the argan nut. Packed with essential fatty acids and Vitamin E. Supports new hair growth and guards against visible signs of damage, mending split ends and helping hair look and feel silky and revitalized.

The Leave in Treatment Ingredients
Castor Seed Oil

A naturally rich source of essential fatty acids. Helps fight scalp inflammation and hydrate the hair shaft, improving elasticity and reducing the risk of breakage.

 The Leave in Treatment Ingredients
Oat Kernel Oil

An omega fatty acid and antioxidant powerhouse. Nourishes, soothes, and supports the elasticity of the hair cuticle, while forming a physical barrier to lock in moisture and prevent water loss, keeping strands plump and hydrated.

The Leave in Treatment Ingredients
Vitamin B5

A super-hydrating soother. Moisturizes and softens from root to tip, making hair easier to comb while boosting strength and shine.

The Leave in Treatment Ingredients
Vitamin E

A restorative anti-oxidant. Fends off damage by blocking free radicals, and helps maintain cellular structure, support barrier function, and optimize hydration levels, for soft, vibrant hair.

The Leave in Treatment Ingredients
Bamboo Extract

Improves hair’s moisture retention so it has a healthy, natural shine. Also helps soothe the scalp, improve blood circulation in the scalp, and fortify hair follicles to encourage regrowth.

Just as our hero skin products provide cells with a repair toolbox, The Leave-In Hair Treatment is a complete array of highly effective ingredients that remind hair follicle cells of their innate ability to regrow and renew the hair. The presence of our proprietary technology, TFC8®, ensures that nutrients are delivered precisely where they are needed to awaken the youthful behavior of healthy, thriving hair.

Professor Augustinus Bader Read About Professor Bader
Customer Reviews

The lip balm is the creamiest, most nourishing I've tried!

Ildiko.

Discover The Hair Collection

Hydrate, nourish, and renew your scalp and hair with cleanly crafted, high performance haircare. Shop Haircare

Frequently Asked Questions

Is it fragrance-free, vegan-friendly and free from?

"The Leave-in Hair Treatment is 100% vegan and free of gluten, GMOs, parabens, silicones, sulfates (SLS, SLES), DEA, fragrance, heavy metals, talc, and petrolatum/paraffin/mineral oil. "

Is the packaging recyclable?

Housed in a 100% recyclable tube made from sustainable sugar cane and 100% recyclable cap. Carton and leaflet are FSC-certified and recyclable.

Is The Leave In Treatment safe to use with color treated hair?

Yes, it's a sulfate-free formula design to maintain your hair color. If you have any concerns, we recommend consulting your hairstylist before use.

Is The Leave-in Hair Treatment safe to use during pregnancy?

Yes, The Leave-in Hair Treatment is safe to use in pregnancy and breastfeeding.

Does The Leave-in Hair Treatment have a fragrance?

The Leave-in Hair Treatment is unscented, with no fragrance added.

How long does The Leave-in Hair Treatment last?

The Leave-In Hair Treatment should last around 2-3 months.

How many times a week shoud I use The Leave-in Treatment?

The Leave-in Hair Treatment can be used 2-3 times per week as needed.

Should The Leave-in Treatment be used before or after hair styling?

The Leave-in Hair Treatment boosts hair-healthy properties of The Conditioner, further enhancing hair's natural growth, strength, shine, and resilience. The Leave-in Treatment offers an instant refresh at any point throughout the day.

Why use both The Conditioner and The Leave-in Hair Treatment?

The Leave-in Hair Treatment boosts hair-healthy properties of The Conditioner, further enhancing hair's natural growth, strength, shine, and resilience. The Leave-in Treatment offers an instant refresh at any point throughout the day.

Can this be used on dry hair or should it only be used on damp hair?

Yes, The Leave-in Hair Treatment can be used on both dry and damp hair.

Can The Leave-in Treatment be used as a heat protector?

The Leave-in Hair Treatment contains multiple powerhouse ingredients that protect against heat and combat damage caused by heat.

Is The Leave-in Treatment safe to use on keratine treated hair?

If you have any concerns, we recommend consulting your hairstylist before use.

Does The Leave-in Treatment can be used as a Sun Care protector?

The Leave-in Hair Treatment contains ingredients that offer natural protection against UV.

Pairs Well With

The Leave-In Hair Treatment pairs well with the following products for your haircare routine

  1. Learn more