Professional use only – for licensed stylists and salons.
Bio Sleek - Permanent Amino Acid Straightening for Professionals
Bio Sleek is a professional amino-acid straightening treatment that permanently smooths and straightens hair while keeping it soft, shiny, and frizz-free. It’s formaldehyde-free, fully rinsed before styling, and ideal for clients who want long-lasting straight hair with simple root retouches every few months.
Bio Sleek Application Tutorial
Video
What exactly is Bio Sleek, and how is it different from keratin or Japanese straightening?
Bio Sleek is a permanent straightening treatment based on amino acids + heat.
- Unlike keratin, there is no product left in the hair – you rinse and shampoo it out before blow-drying and ironing.
- Unlike Japanese straightening, it is formaldehyde-free and gentler on the hair, while still giving very straight, sleek results.
- Once the mid-lengths and ends are treated, they stay straight – on future visits you only treat the roots.
Who is (and isn’t) a good candidate for Bio Sleek?
Great candidates
- Clients who say: “I want my hair straight every day, even after I wash it.”
- Wavy, curly, afro or very frizzy hair that is natural or colored (non-bleached).
Not ideal
- Very damaged, stretchy, breaking hair.
- Clients who love their natural curls and don’t want to lose them.
- Very light or pastel blondes who are better for Nano Silky only (for frizz control without permanent straightening).
Does Bio Sleek need to process under heat, and how long should the hair stay under heat?
Yes. After applying Bio Sleek, the hair must process under heat with a shower cap, and the processing time depends on the hair type.
Normal hair:
- 30 minutes under heat with cap
- 10 minutes without heat
(60 minutes total)
Thick, curly, or resistant hair:
- 60 minutes under heat with cap
- 20 minutes under heat without a cap
- 10 minutes without heat
(90 minutes total)
The hair isn’t fully straight after the first wash – what should I do?
Most of the time this is about technique, not product.
Ask yourself:
- Did I apply in small enough sections and comb through?
- Did I iron in very small sections, slowly, with enough passes?
- Is the hair low-porosity or very resistant?
Correction plan
- If the client has only washed one time, you don’t need to redo the treatment.
- Bring them back and re-flat-iron the hair.
With Nano titanium iron, Tiny sections and 4–6 slow passes (more on resistant areas).
If the client has washed many times and the hair looks almost like before, then book a new full Bio Sleek service.
How do I straighten afro or tight curls with Bio Sleek? Is one session enough?
Yes – one session can be enough, but afro/tight curls need extra respect.
Key rules
- Apply in very small sections, comb through each one.
- Process 60 minutes under heat + 30 minutes without heat and without cap.
- Use a nano titanium iron with:
480°F → about 8–10 passes per section, or
430–450°F → 12–18 passes per section. - Work slowly in tiny sections until the hair looks smooth and shiny.
If, after the first wash, only a few spots still have curl, fix them with a flat iron only.
Color & Bio Sleek
Should I do color before or after Bio Sleek?
For the most controlled result, always think:
Bio Sleek first → then color or toner.
Bio Sleek is an amino-acid treatment + heat, so it can slightly lift or fade color, especially on previously colored or light hair.
If you color before Bio Sleek, the treatment can make the hair a bit lighter or warmer.
If you do Bio Sleek first, and then color, you are putting the final pigment into hair that is already straight – so you see the true final shade.
Rule for stylists:
If you’re not sure what to do → do Bio Sleek first, then color (same day or up to 2 weeks later).
Can I color the hair the same day as Bio Sleek?
Yes – but with rules.
Safest sequence: Bio Sleek first → color after.
Same-day color guide
After Bio Sleek, wash twice with Treatment Care Shampoo, then apply Treatment Care Conditioner for 3 minutes and rinse.
Dry the hair completely.
For roots: use permanent color with 20-volume developer.
For mid-lengths and ends: use a toner (demi or semi) with 1.9% or lower developer.
If you are doing a toner only:
Darker/richer toner: Can be done the same day, right after the Treatment Care wash + dry.
For very light, pastel, or fragile hair, it’s better to wait 2 weeks before doing full color or light toner, so the pigment lasts longer.
Dark toners (going deeper):
Can be applied right after the treatment on clean hair.
Always shampoo and condition before applying the toner.
Light / pastel / fashion toners:
For the best, longest-lasting results, wait 2 weeks after Bio Sleek where possible, especially on level 8+ blondes or heavily highlighted hair.
Because Bio Sleek is amino-acid based and uses heat, very delicate pigments can fade faster if you tone immediately.
How do I work with blondes or bleached hair?
On healthy level-8+ bleached hair, use the Bio Sleek + Nano Silky combination instead of pure Bio Sleek:
- Mix 90% Bio Sleek + 10% Nano Silky.
- Follow the same application and ironing rules, but always:
1. Do a strand test first.
2.Watch the hair closely and reduce heat/passes on fragile areas.
If the blonde is extremely damaged, stretchy, or gummy, skip Bio Sleek and offer Nano Silky (or another smoothing treatment) instead of permanent straightening.
My client with natural white/gray hair turned yellow after Bio Sleek. Why, and what now?
Why it happens
- White/gray hair is very porous and has no pigment.
- Any amino-acid treatment + high heat (not only Bio Sleek) can cause oxidation, making the hair look slightly yellow.
How to correct it
- Use a purple or blue toning shampoo at the bowl, or
- Apply a violet/blue demi toner to neutralize and bring the hair back to a cool gray.
Which flat iron should I use and how many passes?
For Bio Sleek you want:
Flat iron type
- A high-quality nano titanium flat iron with very stable, adjustable heat.
- Recommended: Lizze Extreme flat iron.
General rules for passes
- Work in very thin sections and move the iron slowly.
- The higher the temperature, the fewer passes you should do.
- Do not exceed 8–10 passes at 480°F.
- Always watch the hair – once it looks silky, shiny and soft like butter, you’re done.
How many times a year can I apply Bio Sleek on the roots and on the full length?
Roots / new growth:
- Every 3–6 months, depending on how fast the hair grows and how curly the regrowth is.
Full length:
- Maximum 2–3 times per year on the same hair, only if the hair is still healthy.
- After that, treat roots only and protect the lengths with Nano Silky or Nano Mousse if needed.
Can I combine Bio Sleek on the roots with Nano Silky on the rest of the hair?
Yes, this is a great combo when you want permanent straight roots and silky, frizz-free lengths in one service.
How to do it:
- Wash 2× with clarifying shampoo, rinse and dry the hair 100%.
- Apply Bio Sleek only on the roots / new growth.
- Apply Nano Silky on the mid-lengths and ends (not on the scalp).
- Let both products process (follow your timing chart).
- Rinse the hair completely – remove Bio Sleek and Nano Silky from roots and lengths.
- Blow-dry 100% smooth and flat iron in thin sections.
Result:
- Roots = permanently straight (Bio Sleek)
- Lengths & ends = smooth, soft, shiny, frizz-free (Nano Silky)
Can I combine Bio Sleek on the roots with Nano Mousse on the rest of the hair?
Yes. This is perfect when you want permanent straight roots and 12–16 weeks of smoothing on the mid-lengths and ends.
How to do it:
1.Do Bio Sleek only on the roots:
- Wash 2× with clarifying shampoo, dry 100%.
- Apply Bio Sleek on the new growth, process as usual.
- Rinse the Bio Sleek completely from the roots.
2.Towel-dry the hair so it is damp, not dripping.
3.Apply Nano Mousse on the mid-lengths and ends.
4.Follow the Nano Mousse steps:
- Place the client under the dryer for about 20 minutes.
- After that, blow-dry the hair 100% dry and as smooth as possible.
- Flat iron in small sections, making 4–6 passes per section until the hair is silky and smooth.
Result:
- Roots = permanent straightening from Bio Sleek
- Lengths & ends = smooth, soft, frizz-free for 12–16 weeks from Nano Mousse
