Best Hair Fibers For Thinning Hair

What Works…And What Doesn’t

toppik, caboki and boldify bottles

Full disclosure? I haven’t actually had a chance to use hair fibers yet. Because unfortunately, my hair loss is too widespread for them to take effect.

Back when I had more hair, and fewer bald spots, I used a concealer spray to cover them up – which, at the time, was really effective. But I was still always worried that I’d be discover, as this spray didn’t exactly create the most natural effect. I was also worried about what all the harmful chemicals were doing to my skin.

By the time I read about using hair fibers for thinning hair and hair loss, it was a little too late for me. (I could’ve won a Thinnest Hair Award or as I am now, a Bald Choice Award.) So I don’t want that to be the case for you! Check out how effective they can be in giving you the appearance of thicker, natural hair – and what the top brands are.

Emma's 'I'm not a doctor' disclaimer

Hi there, I’m an alopecian, I’m not a doctor! Any advice I give is based on my own research and personal experiences . This site is, however, reader-supported. When you buy through external links, I may earn a tiny affiliate commission. Learn more here. I also keep the lights on by selling my own headscarves and alopecia merch.
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My Top 3 Hair Fiber Brands

Toppik Hair Fibers

Boldify Hair Fibers

Caboki Hair Fibers

Best Hair Fibers

The following brands share the same goal: to act as a hair restoration treatment for men and women suffering from hair loss. They’re best for those with lightly thinning hair, like at the crown or hairline, or for filling smaller bald patches with natural hair. So while they are suitable for all hair types, you need to have a certain amount of hair to work with!

Hair building fibers aren’t really recommended for those with extensive alopecia as they need hair strands in the first place in order to cling onto. These products work in a similar way – your shake or spray on microfibers that blend with your natural hair to cover areas of thinning hair and create the illusion of fuller hair.

But they differ slightly in terms of ingredients, potential side effects, how to use them and customer reviews.

So let’s check out the top hair fibers for thinning hair!

Most Popular: Toppik Hair Fibers

Toppik hair fibers are one of the most popular hair restoration brands out there, including other hair loss concealers like sprays or powders.

Suitable for all hair types, their thinning hair fibers are made of a Keratin Protein. Keratin is your hair’s natural protein – and as we’re often deficient in keratin, due to environmental factors like sun exposure and humidity or chemicals like salon coloring treatments or heat styling, which can affect hair health, an added dose is definitely A Good Thing.

Keratin protein also combats frizz, provides shiny texture and manageability and in short, makes your existing hair healthier as well as appear thicker. And the results of using Toppik to bulk up thinning hair seem promising, with customers posting some pretty amazing before and after pictures. It also gets 4.3 stars out of a whopping 33,000 reviews on Amazon.

Plus, according to a user survey:

  • 93% say Toppik makes them look younger and more attractive
  • 90% agree Toppik is natural-looking
  • 96% would recommend Toppik keratin hair fibers to others

Not bad, right? And with 9 different hair colors to choose from, there’s bound to be a shade that can blend in easily with your natural hair.

The only downside of Toppik is that it does contain extra chemicals, like ammonium chloride, which might dry out your scalp and wouldn’t be ideal for sensitive skin. But if you want to use these keratin hair fibers for special occasions – especially this version for women, which fills in extension tracks, helps conceal bald spots and visible thinning hair around ponytails, braids and updos – go for it!

Psst…another popluar brand of natural keratin fibers is Cuvva hair building fibers: but I haven’t included this hair fiber product in my list because, in addition to ammonium chloride, Cuvva hair fibers contain DMDM Hydantoin: yet another ingredient that can dry out and irritate the skin.

2. Natural Ingredients: Boldify Hair Fibers

This is the second-most popular hair fiber product on Amazon, with 4.3 stars of out almost 26,000 reviews. Boldify is available in 14 different hair colors, from medium brown to options for graying hair, and is recommended as a hair topper or thickener in both men and women, for all hair types.

It’s the cheapest product on this list (by a few dollars), with advanced hair powder fibers that inlude follicle-mimicking molecules for seamless blending and a natural finish. I also like that Boldify includes a “Color Match Guarantee” – whereby if the color isn’t quite right you can get in touch with their customer service department, who’ll help you select another shade and send it to you, free of charge. Nice touch, guys!

The 100% vegan and cruelty free hair fibers from Boldify come highly recommended by reviewers. Like Caboki (next on the list) their ingredients are simple and natural: only containing Moroccan Gossypium Herbaceum cotton, mineral-based colorants (natural iron oxides) and a little salt.

That’s the only thing that causes me pause about Boldify hair thickening fibers. Because sodium chloride can dry out the scalp and make a keratin protein treatment less successful…so in hindsight, maybe it’s not great for all hair types after all.

This ingredient is often used as a thickener in thinning hair fiber products but I wonder if it’s all that necessary…after all, Caboki manages just fine without it!

3. Natural & Hypoallergenic: Caboki Hair Fibers

This Caboki thinning hair treatment may look like a powder – but each bottle contains thousands, if not more, microfibers that you apply topically to your scalp in areas of thinning hair. You can also get a bottle with a spray applicator nozzle for easier distribution around your scalp.

Caboki’s natural hair fibers have a negative charge to create a strong bond to your hair that lasts all day. And the company says, negatively charged hair fibers are more effective that positively charged ones, which tend to leave the hair flat or dull.

I’m not sure which charge leads to the best results but there’s a lot to like about Caboki. Unlike many other hair fiber products with dozens of ingredients and hidden chemicals, Caboki only contains 2 ingredients: a cotton fiber called Moroccan Gossypium Herbaceum – also known as Levant cotton – and natural minerals to act as colorants.

So, no added fillers, preservatives or chemicals: just natural ingredients that blend easily into your very human hair, leaving it soft and silky. The ultra lightweight hair fibers are hypoallergenic so they truly are great for all hair types, particularly those with a sensitive scalp, and there are 14 shades to choose from, so it’s easy to find a shade close to your natural hair color.

Caboki gets a slightly higher rating on Amazon than Toppik, with 4.4 stars – although that’s from just under 3,000 reviews, so their hair thickening fibers haven’t quite reached the same levels of popularity. Still, I think Caboki sounds like a great brand to try out: whatever your hair type.

Benefits of Hair Fibers

So, now that we’ve looked at the top brands, let’s explore the question: do hair fibers work for thinning hair?

Well, the short answer is yes: if you’re looking to bulk up fine hair or thin hair. Because they don’t use dye your patches like a concealer spray does – they actually cling to the hair you have to give the appearance of fuller hair, whatever your hair type. So hair fibers conceal those bald spots in a more natural way.

In addition to hair illusion, as these hair fibers are made from natural ingredients that support hair growth, they nourish and moisturize the scalp at the same time…not causing the kind of damage or irritation you might get from more chemical-heavy sprays. And even though Toppik contains ammonium chloride, the fact that the keratin proteins can strengthen your existing hair is pretty positive.

Although I wouldn’t expect your hair loss to suddenly stop or for an improvement in hair growth as a result of sprinkling on a hair fiber powder, they do help with confidence. (When applied correctly, that is!) Once you become a dab hand at application, you can rest assured that your hair camouflage is doing its job: your thinning areas are covered and you can go about your day.

And stressing less about your receding hairline might even mean less shedding and who knows, hair growth as a happy side effect!

Finally, although natural fibers aren’t a long-term solution by any means, they are a pretty safe ‘quick fix’ to cover up your hair loss and give new hair illusion, temporarily. Side effects, if any, are minimal and they’re a very affordable option, too. Way, WAY less than going for a hair transplant, for instance – another increasingly popular hair loss treatment.

Downside of Cover-Ups

The first point is a biggie: most hair fibers won’t work if you have widespread hair loss, as they depend you having enough hair to cling to for maximum coverage. So they’re not suitable for anyone with alopecia universalis, alopecia totalis or extensive alopecia areata patches (like I had, before I shaved off the rest).

Ideally, you’d have hair that’s at least 0.5 inches long and patches that aren’t so big that slightly thicker hair on the edges still wouldn’t disguise (Caboki claims their hair fibers give you 10x thicker hair though – so maybe the illusion extends pretty far!)

Plus, although all the brands I’ve reviewed here say their hair fiber products are “weather resistant” I wonder how true this is. You might need to use hair spray for the best results and that removes the “all-natural ingredients” advantage.

I only know that, when I used other hair concealers like a spray, wind, rain and sweat were not my friends. I definitely had a bit of smudging going on – although that was when I was spraying directly onto my bald patches, rather than surrounding hair, so I assume hair fibers are different.

Hair fibers are also supposedly stain-free: but that leaves me to wonder, if they really are all that long-lasting. Should it really be that easy to wash them off? Maybe when it’s when you use soap and water…anyway, potential clothing stains could be an issue!

How to Use Hair Fibers

The process for applying hair fibers is pretty similar across brands. Sprinkle (or spray, if you have an applicator) the hair fibres directly onto your thinning areas, like your hairline or the crown of your head. You don’t need to brush the fibers through or anything, just allow them to rest and bond with your hair upon contact.

Next, wash your hands thoroughly with soap and water, then style your own hair as normal. Your hair fibers should last all day, until your next shampoo – but a small spritz of hair thickening fiber spray, like this Caboki one, is recommended for the best results and a shiny texture, but especially to help the hair fibers stay in place through all weathers.

For the easiest application, Toppik offer a removable spray applicator and a hairline optimizer along with one of their bottles.

Side Effects & Contraindications

As these are natural hair fibers – made from cotton and keratin – side effects are very minimal. But you might see drier or dehydrated locks due to the sodium chloride in Boldify, or the ammonium chloride in Toppik’s keratin proteins. Maybe a little scalp irritation or itchiness too so if that’s the case, go for an all-natural option like Caboki.

The other possible side effect is embarrassment: it will take a little practise to get the hang of these fibers for a natural looking finish. In the meantime, you may see clumpiness, smudges, the appearance of fake hair rather than real hair…but stick with it, you’ll get it right!

In terms of who should avoid using hair fibers, as I’ve mentioned, they’re not really for anyone with extensive hair loss. If this applies to you, I’d recommend trying one of the natural hair loss treatments I recommend in the next section.

Alternative Hair Loss Treatments

If you have widespread areas of thinning hair, or a completely bald head, then there’s no point in using hair fibers. Instead, I’d recommend trying the following hair growth treatment and supplement. Bearing in mind, they may not regrow your hair overnight – but they can certainly point you in the right direction!

Revita from DS Labs

Revita is my top hair loss treatment. An all-natural vegan brand that stopped my hair shedding, massively improved the quality and texture of my existing hair and actually brought a little white vellus fuzz back to my patches, too! Although I unfortunately can’t use their nanoxidl serum during my pregnancy right now, I’m keen to try it after my baby is born – it’s supposed to be as effective as minoxidil, with no side effects!

Revita shampoo bottle

Folexin Supplements

Hair vitamins get to the root cause of your hair los: which could involve chronic inflammation, stress, nutritional deficiencies or hormone imbalances. These hair supplements are a holistic approach towards correcting those triggers and go a long way towards promoting hair growth.

This brand – Folexin – comes highly recommended in online reviews (and from Lady Alopecia readers!) and they’re a really affordable way to both reduce hair thinning and stimulate regrowth…starting with the inside.

folexin supplements

Common Questions

How long do hair fibers last for thinning hair?

The best hair fiber products should last you all day, or until the next time you wash your hair. The amount you use on each application, and how long a bottle will last, really depends on your hair type.

How do I choose the right color?

If you’re unsure between 2 shades e.g. medium brown and dark brown, go for the darker one for maximum coverage (as hair is typically darker at the roots). You can also mix or layer 2 different shades to match your unique hair color!

What are Febron hair building fibers?

Febron hair fibers are another brand of fibers for thinning hair. I haven’t included the brand in my top fibers for thinning hair post because, even though the brand says they’re composed of 100% fibers from a natural source, I couldn’t find out what that source actually is!

Which are the best hair fibers for thinning locks?

Well, that depends really. Your preference might be different to mine…but even though Toppik and Boldify are much more popular, I quite like the fact that Caboki are completely natural. That’s the brand I’d choose first – I feel like it’s the best hair fiber – although you could try Toppik and, if you don’t have any reactions l ike an irritated scalp, stick with it!

Final Thoughts: Cover Up With Confidence!

Although I prefer to wear one of my colorful headscarves on the days when I lack confidence, that might not be your style. Maybe you just want to look like your usual self, with a cover-up option that blends in easily for a natural effect.

In that case, fibers for thinning hair can be your new best friend. Once you find a brand and a color that speaks to you, take some time to practice. Master the art of application and cover up those bald spots or thinning hair whenever you feel you need to. Perhaps switching up your shampoo to a more natural, sulfate-free option and taking some hair vitamins while you’re at it.

I hope this post has helped you in determining which is the best hair fiber for thinning hair – and how to use them on your own thinning hair, too!

Now go forth with confidence and enjoy feeling like “you” again.

Love & hugs,

Lady Alopecia Signature

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Lady Alopecia

Alopecian. Yoga Teacher. Copywriter. Here to share information, offer support and show people the adventures that can lie in hair loss. I’m proud to have alopecia and I want to help others embrace their baldness, too!

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