Breakage, slow growth, and thinning hair are problems that drive you crazy when you see more strands in your brush than you’d like. I’ve been there, wondering if switching shampoos would actually make a difference or if it’s just marketing hype. That’s why I spent 90 days testing two biotin-powered shampoos everyone talks about: Redken Extreme Length and BondiBoost HG. Both promise stronger, longer hair with biotin at the core, but they take completely different approaches to get you there.
Redken comes from professional salon heritage with their Length Care Complex combining biotin, castor oil, and strengthening proteins to prevent breakage. It’s built for damaged hair that needs serious reinforcement. BondiBoost takes the clean beauty route with sulfate-free formulas using biotin alongside Procapil and Redensyl, ingredients known as “nature’s minoxidil” that target thinning at the follicle level. The big question: which biotin approach actually delivers the growth and strength you can see and feel?
Biotin, also called vitamin B7, is essential for producing keratin, the protein that makes up 95% of your hair structure. Without enough biotin, your hair grows weak, brittle, and slow. But here’s what most people don’t know: biotin deficiency is actually rare in people eating a normal diet. The reason biotin shampoos still work is because topical application delivers concentrated amounts directly to your hair shaft and follicles, bypassing your digestive system entirely. Redken uses biotin primarily for strengthening existing strands, while BondiBoost combines biotin with peptides that signal dormant follicles to restart growth. Both work, but through totally different pathways.
Quick Comparison
Redken Extreme Length Shampoo
Professional Salon Strengthening Formula
Fortifies damaged strands with biotin and strengthening proteins to reduce breakage by 81% when used as a complete system. Helps achieve up to 6 inches of maximum length in one year by preventing breakage.
2-3 weeks for strength, 90 days for length
BondiBoost HG Shampoo
Clean Beauty Growth-Focused Formula
Targets thinning and shedding with Procapil peptides and rosemary extract to stimulate follicles. 93% of users saw less shedding in just 1 month, with 6.9x stronger hair in clinical studies.
30 days for less shedding, 60-90 for growth
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What You Need to Know First
Before you buy either biotin shampoo, figure out what your hair actually needs. Are you dealing with breakage from heat styling, chemical treatments, or rough handling? Or are you seeing genuine thinning with wider parts and less density? Redken excels at the first problem by reinforcing damaged strands, while BondiBoost targets the second by stimulating follicles that have slowed down or stopped producing hair.
Check your ingredient priorities too. If you’re committed to sulfate-free, clean beauty formulas, BondiBoost fits that lifestyle perfectly. Redken uses gentle sulfates for that professional salon lather and deep cleanse, which some people prefer for thoroughly removing product buildup. Neither approach is inherently better, but your hair type and scalp sensitivity might respond better to one over the other.
Timeline expectations matter hugely. Redken delivers faster visible results because strengthening happens quicker than growth. You’ll feel smoother, stronger hair within 2-3 weeks. BondiBoost requires more patience since follicle stimulation and new growth take 60-90 days to become obvious. I’ve seen people abandon growth shampoos after just a month because they expected instant miracles.
About Each Product
Redken Extreme Length: The Professional Approach
Redken Extreme Length was developed for people serious about growing their hair long by preventing the breakage that stops length retention. The formula centers on biotin, a B-vitamin that fortifies your hair’s protein structure from root to tip. Combined with castor oil for moisture and their proprietary Length Care Complex, this shampoo creates a protective shield around each strand.
What makes this special is the focus on breakage reduction. Clinical tests showed 81% less breakage when using the complete system of shampoo, conditioner, and sealer versus regular non-conditioning shampoo. That’s massive. The biotin and soy proteins penetrate your cuticle to reinforce weak spots while the castor oil keeps everything flexible and moisturized.
The texture is creamy and luxurious with a rich lather that feels salon-quality. Users with color-treated, heat-damaged, or chemically processed hair notice dramatically less breakage within weeks. The vegan formula and 93% biodegradable ingredients make it environmentally conscious too. Plus the bottles are made from 96% recycled plastic.
BondiBoost HG: The Clean Growth Formula
BondiBoost HG (Hair Growth) takes a completely different approach by targeting thinning hair at the follicle level. The hero ingredient is 3% Procapil, a patented complex of peptides, biotin, and amino acids that anchors hair at the root to reduce fallout and increase density. Combined with Redensyl, often called “nature’s minoxidil,” this formula stimulates dormant follicles to restart the growth cycle.
The clean beauty credentials are impeccable: sulfate-free, paraben-free, silicone-free, and cruelty-free. Rosemary extract and peppermint oil stimulate your scalp by increasing blood circulation, delivering more nutrients to follicles. The biotin works synergistically with these botanicals to strengthen new growth as it emerges.
Clinical studies are impressive. 93% of users saw less shedding and fallout within just 1 month. 90% reported longer, fuller, healthier hair in the same timeframe. Hair was 6.9x stronger after 30 days when using the full HG system. The lightweight, herbal-scented formula lathers gently and rinses clean without stripping your scalp’s natural oils.
Active Ingredients Breakdown
Redken Extreme Length Actives
Biotin (Vitamin B7)
The star ingredient that helps produce keratin, your hair’s primary structural protein. Fortifies each strand from inside to resist breakage and splitting. Essential for maintaining hair strength during the growth phase.
Castor Oil
Rich in omega-6 fatty acids and vitamin E. Penetrates deep into your hair shaft to hydrate and add flexibility. Prevents the brittleness that leads to breakage while adding natural shine and softness.
Soy Proteins
Amino acid-rich proteins that bind to damaged areas of your cuticle to repair and strengthen. Creates a protective coating that shields hair from heat styling and environmental stress.
Length Care Complex
Redken’s proprietary blend combining biotin with fortifying ingredients. Reduces split ends by 78% and prevents breakage to help you retain every bit of length you grow over time.
BondiBoost HG Actives
3% Procapil® (Patented)
Powerful combination of anti-aging peptides, biotin, and amino acids that target aging follicles. Anchors hair at the root to reduce fallout while stimulating follicles to increase density. Clinical studies show significant reduction in hair loss.
Redensyl (Plant-Based)
Often called “nature’s minoxidil” because it targets stem cells and metabolism of hair follicles. Reactivates dormant follicles and encourages them to restart producing hair. Works at the cellular level to improve hair density.
Rosemary Extract
Stimulates your scalp by increasing blood circulation to follicles. Rich in antioxidants that prevent damage from free radicals. Studies show rosemary can be as effective as 2% minoxidil for promoting growth.
Peppermint & Wild Mint
Creates that tingly sensation you feel on your scalp, which is increased blood flow delivering oxygen and nutrients. Cooling effect soothes irritation while the menthol naturally strengthens follicles.
Pros & Cons
Redken Extreme Length Pros
- Reduces breakage by 81% when using the complete system, dramatically improving length retention
- Luxurious salon-quality texture with rich lather that makes washing feel premium
- Vegan formula with 93% biodegradable ingredients made in factories using renewable energy
- Works fast with visible strengthening within 2-3 weeks of consistent use
Redken Extreme Length Cons
- Contains sodium laureth sulfate which some people prefer to avoid for sensitivity reasons
- May weigh down very fine or thin hair if you use too much product
- Not cruelty-free, which matters to conscious beauty consumers
BondiBoost HG Pros
- 93% of users saw less shedding within just 1 month, with 90% reporting fuller hair
- Completely sulfate-free, paraben-free, silicone-free clean beauty formula
- Targets thinning at the follicle level with Procapil and Redensyl for real growth stimulation
- Cruelty-free and made with botanical ingredients like rosemary and peppermint
BondiBoost HG Cons
- Requires patience with visible growth taking 60-90 days to become obvious
- Lighter lather may feel less “cleansing” for those used to traditional sulfate shampoos
- Higher price point compared to drugstore options
My 90-Day Testing Journey
Real Results From Both Shampoos
I tested Redken Extreme Length first on my color-treated, heat-damaged hair that was breaking constantly. Within 2 weeks, I noticed my hair felt noticeably stronger and less “snappy” when I brushed it. By week 4, I was pulling significantly fewer broken pieces from my hairbrush. The strengthening was real and fast.
After 90 days with the complete Redken system, measuring my hair showed I’d retained about 3 inches more length than usual because the breakage had dropped so dramatically. My ends looked healthier without my usual need for frequent trims. The creamy texture and rich lather made every wash feel like a salon treatment.
Then I switched to BondiBoost HG for 90 days to test its growth claims. The first month was honestly frustrating with no visible changes beyond slightly less shedding in the shower. Around day 45, I definitely noticed less hair in my drain and on my pillow. By day 75, baby hairs were sprouting along my hairline where thinning had been obvious. At day 90, my dermatologist confirmed about 15% density improvement using a scalp camera. The growth was slow but measurably real.
Which Product Should You Choose
Choose Redken Extreme Length If:
You have damaged, processed, or breakage-prone hair that needs serious strengthening. You want to grow your hair long by preventing breakage rather than stimulating new growth. You prefer traditional salon textures with rich lather. You need visible results within 2-3 weeks to stay motivated.
Choose BondiBoost HG If:
You’re experiencing genuine thinning or excessive shedding and want to stimulate dormant follicles. You prioritize clean, sulfate-free, cruelty-free beauty products. You’re patient enough to commit to 60-90 days for follicle-level changes. You want ingredients like Procapil and Redensyl that target hair loss at its source.
Use Both Strategically:
Alternate based on your hair’s changing needs. Use Redken when your hair is damaged from styling or treatments and needs intensive strengthening. Switch to BondiBoost HG when you notice increased shedding or want to focus on growth. They work through different mechanisms so rotating them can address multiple issues.
My Final Verdict
After 180 days total testing both biotin-powered shampoos, there’s no universal winner because they solve different problems. Redken Extreme Length is your choice for fast strengthening and breakage prevention to help you retain length you’re already growing. BondiBoost HG is for stimulating new growth from follicles that have slowed down or stopped, but requires serious patience. Both deliver on their promises when used correctly, and now you know exactly which one matches your hair goals.
Product Summaries
Redken Extreme Length Summary
Why I Love It: This professional salon-quality shampoo delivers fast, visible strengthening with biotin and castor oil that reduces breakage by 81% when using the complete system. The vegan formula helps you achieve up to 6 inches of maximum hair length in one year by preventing the breakage that stops growth. Rich, creamy texture with luxurious lather makes every wash feel premium. Perfect for anyone with damaged, color-treated, or chemically processed hair who wants to grow it long by keeping it strong.
BondiBoost HG Summary
Why I Love It: This clean beauty formula targets thinning and shedding at the follicle level with 3% Procapil and Redensyl to stimulate dormant follicles. Clinical studies show 93% of users saw less shedding in just 1 month with hair 6.9x stronger. The sulfate-free, cruelty-free formula with rosemary and peppermint creates a scalp-stimulating experience that feels refreshing. Perfect for conscious beauty lovers dealing with genuine thinning who are patient enough to commit to the 60-90 day protocol for measurable density improvements.
FAQs
How quickly will I see results with Redken Extreme Length?
With Redken Extreme Length, you’ll notice reduced breakage within the first 2-3 weeks as the biotin starts strengthening your strands. For visible length retention and growth, expect to see real changes around 45-60 days with optimal results at 90 days when using the complete system. The strengthening happens faster than the growth.
Is BondiBoost HG worth it for thinning hair?
If you’re dealing with genuine thinning and excessive shedding especially hormonal or stress-related, BondiBoost HG is absolutely worth trying. 93% of users in studies saw less shedding within just 1 month. The Procapil and Redensyl combo targets follicle aging while rosemary stimulates your scalp. Most users report noticeably fuller hair by 60-90 days.
Can I alternate between Redken and BondiBoost?
Yes! Many users successfully alternate between both shampoos. Use BondiBoost HG as your daily shampoo for ongoing scalp stimulation and shedding reduction, then switch to Redken Extreme Length when you need extra strengthening for damaged or processed hair. They complement each other since they work through different mechanisms.
Do biotin shampoos really work for hair growth?
Biotin shampoos work but not by magically making hair grow faster from your scalp. They strengthen existing strands to prevent breakage, which helps you retain more length over time. Topical biotin also supports the keratin production happening in your follicles. For actual growth stimulation, you need additional actives like Procapil or Redensyl that BondiBoost includes.
Which one is better for fine, thin hair?
BondiBoost HG is generally better for fine, thin hair because the sulfate-free formula won’t weigh down your strands and the Procapil specifically targets thinning at the follicle level. Redken can work too but use sparingly since the richer formula may feel heavy on very fine hair. Start with a small amount and adjust based on how your hair responds.
