Best Curly Hair Building Fibers in 2026

Daisy
Last Updated: Jul 20, 2026

At a Glance: Our Top Picks for Curly Hair Building Fibers

Hair Illusion Black Real Hair Fibers for Thinning Hair - 100% Natural Texture, Non Synthetic Hair Fibers - Bald Spot Cover Up for Women & Men - 38 Gram
#TOP1
Hair Illusion Black Real Hair Fibers For Thinning
9.3
PM SCORE
Hair Illusion Black Real Hair Fibers for Thinning Hair - 100% Natural Texture, Non Synthetic Hair Fibers - Bald Spot Cover Up for Women & Men - 18 Gram
#TOP2
Hair Illusion Black Real Hair Fibers For Thinning
9.3
PM SCORE
Hair Building Fibers, Hair Thickening Fibers for Thinning Hair & Bald Spots Thicker Fuller Hair in 15 Seconds Suitbable for Man and Woman 0.97Oz(Black)
#TOP3
Hair Building Fibers, Hair Thickening Fibers For Thinning
9.3
PM SCORE

* PickSmartly editors independently research, review, and endorse the top products through comprehensive data analysis. We may earn a commission for qualifying purchases made through our product links.

Summary of the Best Curly Hair Building Fibers of 2026

Market Overview
Curly Hair Building Fibers Reviewed
  • Reviews Analyzed: 8214 Items
  • PM Avg. Rating: 7.2 / 10
15 Products Evaluated
  • Highest Price: $75.00
  • Lowest Price: $8.12
  • Avg. Price: $20.26

Hair Illusion Black Real Hair Fibers For Thinning Hair - 100% Natural Texture, Non Synthetic Hair Fibers - Bald Spot Cover Up For Women & Men - 38 Gram

HAIR ILLUSION
38GBLACK
4.72 X 1.77 X 1.77 Inches
0.13 Pounds
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Hair Illusion Inc 9.45

Features

CREATES A FULLER, THICKER APPEARANCE: Eliminate the unwelcome appearance of thinning hair with the natural REAL hair building fibers in Hair Illusion. Ideal for both men and women, the hair thickener uses real hair fibers, allowing you to instantly create the appearance of a thicker, fuller head of hair for a more youthful look.

SUPERIOR ALL DAY HOLD: Never flakey, the hair concealer is made with natural real hair fibers that will not stain the scalp, the pillow or clothing. It is recommended that individuals wear a nightcap or doo rag to extend the lifespan of each application.

NATURAL HAIR FIBERS: Made with 100% natural real hair fibers, Hair Illusion is completely natural for a discreet look that is undetectable. Also great for covering scars and cleaning up patchy beards, the natural hair fibers seamlessly blend with the existing hair with no unsightly transition

PERFECT FOR ALL HAIR TYPES: Available in multiple shades to best match your natural color, the premium natural hair thickener is perfect for all hair types, including naturally curly hair, coarse, medium and fine hair

SYNTHETIC FREE: Free from dyes, powders and synthetic ingredients such as keratin fibers, Hair Illusion’s real hair fibers electrostatically bond to your existing hair and scalp for a naturally thicker appearance. For an improved hold, use with Hair Illusion Fiber Hold On Spray

#TOP2

Hair Illusion Black Real Hair Fibers For Thinning Hair - 100% Natural Texture, Non Synthetic Hair Fibers - Bald Spot Cover Up For Women & Men - 18 Gram

HAIR ILLUSION
713807586591
18.00 Grams
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Hair Illusion Inc 9.79

Features

CREATES A FULLER, THICKER APPEARANCE: Eliminate the unwelcome appearance of thinning hair with the natural REAL hair building fibers in Hair Illusion. Ideal for both men and women, the hair thickener uses real hair fibers, allowing you to instantly create the appearance of a thicker, fuller head of hair for a more youthful look.

SUPERIOR ALL DAY HOLD: Never flakey, the hair concealer is made with natural real hair fibers that will not stain the scalp, the pillow or clothing. It is recommended that individuals wear a nightcap or doo rag to extend the lifespan of each application.

NATURAL HAIR FIBERS: Made with 100% natural real hair fibers, Hair Illusion is completely natural for a discreet look that is undetectable. Also great for covering scars and cleaning up patchy beards, the natural hair fibers seamlessly blend with the existing hair with no unsightly transition

PERFECT FOR ALL HAIR TYPES: Available in multiple shades to best match your natural color, the premium natural hair thickener is perfect for all hair types, including naturally curly hair, coarse, medium and fine hair

SYNTHETIC FREE: Free from dyes, powders and synthetic ingredients such as keratin fibers, Hair Illusion’s real hair fibers electrostatically bond to your existing hair and scalp for a naturally thicker appearance. For an improved hold, use with Hair Illusion Fiber Hold On Spray

Hair Building Fibers, Hair Thickening Fibers For Thinning Hair & Bald Spots Thicker Fuller Hair In 15 Seconds Suitbable For Man And Woman 0.97Oz(Black)

FIND BACK
GS-HAIRFIB01
0.06 Pounds
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
JHZZDZSWYXGS-US 9.91

Features

【Advanced technology】Electrostatic microfiber, powder combined with hair, immediately ensure that your hair is thick and fluffy. Instant hair fillers can cover baldness and fill sparse hair, making hair look thicker and fuller.

【Seamless Fusion】Mixed keratin fibers and real hair can be seamlessly mixed, imitating hair follicle molecules, and can be seamlessly mixed to make the hair look natural and plump, enough to increase the texture and bulk of the hair.

【Natural fiber】 The unique formula is also very friendly to sensitive scalp. This increased hair fiber is a boon for people with thinning hair and hair loss.

【Quick and lasting】 High-quality hair fiber can cover and fill thin hair in a few seconds. Hair growth fiber can be effective for a long time and is very suitable for dating, work, travel, etc.

【Unisex】Aliver Natural hair fibers can be used for straight hair, wavy curly hair and other types of hair. Make your hair thick, healthy and natural.

#TOP4

Hair Illusion Combo Kit - Hold Spray, 38G Hair Fiber Bottle, Applicator & Hairline Optimizer (Black)

HAIR ILLUSION
HI-DISPL
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Hair Illusion Inc 9.45

Features

Hair illusion Combo Pack Kit - Includes 38g Black Fibers, Applicator & Holding Spray Everything You Need in One Kit!

CREATES A FULLER, THICKER APPEARANCE: Eliminate the unwelcome appearance of thinning hair with the natural REAL hair building fibers in Hair Illusion. Ideal for both men and women, the hair thickener uses real hair fibers, allowing you to instantly create the appearance of a thicker, fuller head of hair for a more youthful look.

SUPERIOR ALL DAY HOLD: Never flakey, the hair concealer is made with natural real hair fibers that will not stain the scalp, the pillow or clothing. It is recommended that individuals wear a nightcap or doo rag to extend the lifespan of each application.

NATURAL HAIR FIBERS: Made with 100% natural real hair fibers, Hair Illusion is completely natural for a discreet look that is undetectable. Also great for covering scars and cleaning up patchy beards, the natural hair fibers seamlessly blend with the existing hair with no unsightly transition

PERFECT FOR ALL HAIR TYPES: Available in multiple shades to best match your natural color, the premium natural hair thickener is perfect for all hair types, including naturally curly hair, coarse, medium and fine hair.

Hair Building Fibers With Spray, Hair Thickening Fibers For Thinning Hair & Bald Spots Thicker Fuller Hair In 15 Seconds Suitbable For Man And Woman 0.97Oz(Black)

FIND BACK
JH-HAIRFIBAR01
0.06 Pounds
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
JHZZDZSWYXGS-US 9.89

Features

【Advanced technology】Instant hair fillers can cover baldness and fill sparse hair, making hair look thicker and fuller.

【Seamless Fusion】Mixed keratin fibers and real hair can be seamlessly mixed, hair thickening fiber imitating hair follicle molecules, enough to increase the texture and bulk of the hair.

【Natural fiber】The unique formula is also very friendly to sensitive scalp. This increased hair fiber is a boon for people with thinning hair and hair loss.

【Quick and lasting】 High-quality hair fiber can cover and fill thin hair quickly. Hair growth fiber can be effective for a long time and is very suitable for dating, work, travel, etc.

【Unisex】Professional quality fiber hair powder can be used for straight hair, wavy curly hair and other types of hair. Make your hair thick, healthy and natural.

Hair Fibers 2 In 1 Kit Set Includes Black Hair Thickening Fibers & Spray Applicator Pump Nozzle, Hair Building Fibers, Get Instantly Thick, Full, Shiny Hair In 15 Seconds, For Men And Women

ALIVER
FB19949
6.38 X 5.43 X 2.17 Inches
0.06 Pounds
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
JHXBLMYYXGS-US 8.79

Features

NATURAL HAIR FIBERS + SPRAY BOTTLE FOR HAIR: Made of natural fibers to bond, thicken, and conceal thinning hair instantly, effectively, accurately, and undetectably. The fiber spray applicator disperses fibers evenly, uniformly, and fast to achieve results instantly!

PERFECT FOR ALL HAIR TYPES: Available in multiple shades to best match your natural color, the premium hair thickener is perfect for all hair types, including naturally curly hair, coarse, medium and fine hair.

LASTS ALL DAY: Hair building fibers is rain, wind and sweat resistant and will last right up until your next shampoo. Does not clog scalp pores! (but hair must be fully dry prior to applying the fibers. Best applied on clean and dry hair).

NO HARMFUL CHEMICALS: Our fibers are made from a 100% natural fibers source and are Alcohol, Gluten and Paraben free - conceal thinning hair instantly & undetectable.

WORKS AMAZING FOR MEN AND WOMEN: Our hair loss thickening fibers instantly boost your confidence, appearance, fullness, and boldness.

Hair Fibers 2 In 1 Kit Set, Dark Brown Hair Fiber Spray, Includes 100% Undetectable Natural Thickening Fibers & Spray, Achieve A Fuller And Thicker Fuller Hair, For Men And Women

ELBBUB
1
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING

Features

Create A Denser Look-- Use our hair-increasing fiber to eliminate your troubles of thinning hairand,once applied it makes thinning hair appear thicker and fuller. Hair thickening fibers can immediately cover your sparse areas, make you younger and more confident.

Natural Hair Fiber-- Made of 100% natural real hair fiber, it is safe and natural, giving you the most realistic hair shine effect, seamlessly connecting with existing hair. We responsibly and sustainably source only the finest ingredients ,no dyes, no synthetic ingredients- such as keratin fibers.

Easy To Apply-- Our sprayer can accurately help you apply evenly to your sparse areas, seamlessly connect with the existing hair, and there will be no unsightly fiber clumps. If necessary, adjust the fiber with a comb or hand.

Suitable For Any Type Of Hair -- our natural hair-increasing fiber is your best choice. Whether you have straight, curly, thick or short hair, you can use our products, and the color is also similar to existing hair Matching is your perfect solution.

100% After-Sales-- In the process of using the product, you can consult us if you have any questions, and we will reply to you in time.

Hair Fibers Powder For Thinning Hair & Hair Loss, Waterproof Hair Thickening With Spray Applicator For Men Women,Bald Spots Filler,Undetectable & Instant Thick,Full,Shiny Hair In 15 Seconds,Dark Brown

PEPHUCA
6792909724
0.06 pounds
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING

Features

Hair Thickening Products for Women and Men: Our hair thickening spray is suitable for ladies and men. It will give an instant appearance of a thick, full head of hair within 15 seconds, makes you look younger and more attractive.

100% Undetectable: This hair fibers are totally undetectable even under ultra bright stage lights and camera. No one will know you are using hair fibers unless you tell them. Just get fuller hair, and revive your confidence!

Long Lasting: Our hair fiber spray is windproof, sweatproof, waterproof, and can last all day, so you can go out with confidence. It can be easily washed off with shampoo.

Natural Formula: Our hair dye ingredients are all natural and non-toxic, which added natural substances like plant keratin and plant fibers. Without damaging your hair roots and weighing your hair down, our hair fiber can be thickened to cover your balding area and make you young at once.

Easy to Use & All Hair Types: Our hair thickener comes with spray applicator, so you can spray the hair fiber directly on your head. It is suitable for any kind of hair types or textures, including straight, wavy and curly.

Hair Fibers For Thinning Hair, Natural Formula Hair Fiber, Hair Building Fibers Refill Thicker Hair In 15 Seconds, Conceals Hair Loss & Look Younger For Men Women (Black Without Spray Applicator)

ELAIMEI
HAIR FIBERS
0.06 Pounds
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
FCZJYUS 9.80

Features

【Black Hair Fibers for Thinning Hair】Hair building fibers instantly give you the look of thicker fuller hair in 15 seconds or less, our fibers intertwine with your existing hair for a completely natural look, makes you look younger and more attractive.

【Safe Natural Ingredients】Made of natural, colored fibers that are naturally statically charged. Premium hair loss concealer for thinning hair, 0.97oz/27.5g.

【Last All Day】Our hair fiber is wind, rain and sweat resistant and will last right up until your next shampoo, you can even sleep with the hair fibers still in place!

【100% Undetectable】Our hair fibers is a cosmetic product made from natural keratin which is the same protein compound found in real human hair, it is nearly identical to human hair. It totally undetectable even uder ultra bright stage lights and camera. No one will know you are using hair fibers unless you tell them. Get fuller hair, and revive your confidence.

【For Any Hair Type】Our hair fibers suitable for any kind of hair types and textures, including straight, wavy, curly, and coily. Also for Caucasian hair, Asian hair, and African-American hair. Suitable for Men & Women.

Hair Illusion Keratin Hair Fibers (Black) 100% Natural Looking Hair Fibers. Instantly Conceal Thinning Hair, Bald Spots & Root Cover Up. For Women & Men - 27.5G Large Bottle

HAIR ILLUSION
HI-KERATIN-BL
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Hair Illusion Inc 9.45

Features

CREATES A FULLER, THICKER APPEARANCE: Eliminate the unwelcome appearance of thinning hair with the natural KERATIN hair building fibers in Hair Illusion. Ideal for both men and women, the hair thickener uses keratin hair fibers, allowing you to instantly create the appearance of a thicker, fuller head of hair for a more youthful look.

SUPERIOR ALL DAY HOLD: Never flakey, the hair concealer is made with natural hair fibers that will not stain the scalp, the pillow or clothing. It is recommended that individuals wear a nightcap or doo rag to extend the lifespan of each application.

NATURAL HAIR FIBERS: Made with 100% natural keratin hair fibers, Hair Illusion is completely natural for a discreet look that is undetectable. Also great for covering scars and cleaning up patchy beards, the natural hair fibers seamlessly blend with the existing hair with no unsightly transition

PERFECT FOR ALL HAIR TYPES: Available in multiple shades to best match your natural color, the premium natural hair thickener is perfect for all hair types, including naturally curly hair, coarse, medium and fine hair.

ROOT CONCEALER. Ideal to blend in roots and conceal grey hair.

Kaal Hair Fiber, Hair Fibers For Thinning Hair For Women & Men, (0.97 Oz, Medium Brown) Hair Building Fibers, Completely Conceals Hair Loss In 15 Sec - 8 Shades For Men Women, Instantly Thicker

KAAL
‎KAAL-BTL-01
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
KAAL COSMETIC 6.49

Features

EFFORTLESS TO IMPLEMENT: Hair Fiber attaches securely to your hair, providing it with a realistic, more voluminous, and bulkier look instantly. With Hair Texture Powder, wave goodbye to long-lasting hair care. Hair Styling Powder is user-friendly and blends smoothly into your hair, leaving no mess or stain.

INSTANTLY EFFECTIVE: Hair Powder for Men & Women Instantly transforms your Hair Loss! KAAL- Hair Fibers are easy to apply with no mess or residue, and they are suitable for all hair types. Hair Powder adds natural-looking coverage to bald spots and thinning hair, enhancing your hair color and texture.

LASTS ALL DAY:Transform your hair and keep it looking great all day with our long-lasting Hair Powder! Due to our long-standing Hair Fibers, your tresses will stay looking fabulous throughout the day. Hair Fibers for Thinning Hair Men & Women, attach to your hair seamlessly, providing it with an instantaneous full and dense appearance.

SUITABLE FOR ALL HAIR TYPES: KAAL - Hair Fiber works with all hair types and the perfect solution for anyone looking to achieve fuller, thicker, and more natural-looking hair. Whether you have thin, fine, or curly hair, Hair Fibers for Thinning Hair for Women & Men is safe and effective for all hair types.

NATURAL LOOKING: Our specifically concocted Hair Fibers for Thinning Hair Men & Women producing a realistic looking hair that is both full and textured. No matter what kind of hair you possess, Hair Building Fibers are safe and successful for all hair types, permitting you to accomplish the desired natural look.

Kaal Hair Fiber | Hair Powder, Hair Fibers For Those Experiencing Hair Loss, 0.97Oz - Hair Powder For Men - Women, Conceal Thinning Hair Areas, Hair Texture Powder (Dark Brown)

KAAL
‎KAAL-BTL-01
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
KAAL COSMETIC 4.95

Features

EFFORTLESS TO IMPLEMENT: Hair Fiber attaches securely to your hair, providing it with a realistic, more voluminous, and bulkier look instantly. With Hair Texture Powder, wave goodbye to long-lasting hair care. Hair Styling Powder is user-friendly and blends smoothly into your hair, leaving no mess or stain.

INSTANTLY EFFECTIVE: Hair Powder for Men & Women Instantly transforms your Hair Loss! KAAL- Hair Fibers are easy to apply with no mess or residue, and they are suitable for all hair types. Hair Powder adds natural-looking coverage to bald spots and thinning hair, enhancing your hair color and texture.

LASTS ALL DAY:Transform your hair and keep it looking great all day with our long-lasting Hair Powder! Due to our long-standing Hair Fibers, your tresses will stay looking fabulous throughout the day. Hair Fibers for Thinning Hair Men & Women, attach to your hair seamlessly, providing it with an instantaneous full and dense appearance.

SUITABLE FOR ALL HAIR TYPES: KAAL - Hair Fiber works with all hair types and the perfect solution for anyone looking to achieve fuller, thicker, and more natural-looking hair. Whether you have thin, fine, or curly hair, Hair Fibers for Thinning Hair for Women & Men is safe and effective for all hair types.

NATURAL LOOKING: Our specifically concocted Hair Fibers for Thinning Hair Men & Women producing a realistic looking hair that is both full and textured. No matter what kind of hair you possess, Hair Building Fibers are safe and successful for all hair types, permitting you to accomplish the desired natural look.

Moulis Hair Building Fiber Thicker Fuller Hair In 15 Seconds Natural Formula,Conceal

MOULIS
MOULIS
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Lanlongshangmao SHOP 5.60

Features

Hair building fibers: Use plant sources to make hair fiber, the color matches the existing hair strands, which can make you the perfect solution for regenerative hair product therapy to increase hair volume and thickness.

Fast and lasting: What we produce is high-quality hair that covers and fills fine hair in a few seconds. Hair growth fiber can be effective for a long time and is very suitable for dating, work, travel, etc.

Perfect coverage: light, shiny, realistic hair: celebrity stylists like how these static-charged hair-building fibers instantly cover every gap, adding shine that lasts all day.

Quick and easy application: make you look and feel 10 years younger in 15 seconds, no itching guaranteed! Just shake and spray thicker hair within 30 seconds for longer-lasting coverage.

Hair fibers for thinning hair: Natural hair fillers can be used for straight hair, wavy curly hair and other types of hair. Make your hair thick, healthy and natural.

#TOP14

Vzdsddef Shiny Hair Get Hair Thick Fibers Fibers Hair Full Thickening Instantly Black Hair Care Buh292

VZDSDDEF
PBKAW1TD
0.22 Pounds
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Lynn2021 4.25

Features

LASTS ALL DAY: Hair Building Fibers Is Rain, Wind And Sweat And Will Last Right Up Until Your Next Shampoo. Does Not Clog Scalp Pores! (but Hair Must Be Fully Dry To Applying The Fibers. Applied On Clean And Dry Hair).

Package Content: 1 X Hair Fibers

WORKS AMAZING FOR MEN AND WOMEN: Our Hair Loss Thickening Fibers Instantly Your Confidence, Appearance, , And Boldness.

PERFECT FOR ALL HAIR TYPES: Available In Multiple Shades To Best Your Natural Color, The Hair Thickener Is Perfect For All Hair Types, Including Curly Hair, Coarse, Medium And Fine Hair.

NATURAL HAIR FIBERS: Made Of Natural Fibers To Bond, Thicken, And Conceal Thinning Hair Instantly, Effectively, Accurately, And Undetectably. The Fiber Spray Applicator Disperses Fibers Evenly, Uniformly, And Fast To Achieve Results Instantly!

#TOP15
Best For Fine

Hair Fibers For Thinning Hair For Women Men, Hair Filler Fill In Fine Or Thinning Hair, Hair Thickener Building Fibers, Completely Conceals Hair Loss 0.98 Oz Bottle (Dark Brown)

ZENTANMEI
SELLER SELLER SCORE AMAZON FULFILLED PRIME FREE SHIPPING
Zentanmei Direct US 5.13

Features

【Hair Filler Powder Easy To Apply】Shake The Bottle Sideways Before You Apply Thick Fiber Into Thinning Areas. Apply The Hair Fiber Powder In A Salt And Pepper Direction On Dry Hair. Get Fuller Hair, And Revive Your Confidence. Please Note This Product Is For Spots Where The Hair Is Thinning, And Not For Completely Bald Spots

【Hair Fibers For Thinning Hair For Women Men】Hair Fiber Suitable For All Hai, Available In Multiple Shades To Best Match Your Natural Color, The Premium Natural Hair Thickener Is Perfect For All Hair Types, Including Naturally Curly Hair, Coarse, Medium And Fine Hair

【Natural Hair Filler】Completely Made Of A Natural Ingredient,They Do Not Contain Any Chemical Colourants Or Preservatives, Ensuring An Extremely Natural Hair Look And Avoiding Any Risk Of Allergies.

【Hair Building Fibers Weatherproof】Weather-Proof And Lasting All-Day, Hair Fibers Powder Contains Statically Charged Microfibers, Which Attach Seamlessly To Your Hair Without Causing Skin Irritation And Resist Sweat, Wind, And Rain

【Hair Types】Fibers Are Able To Adhere To Anytype Of Hair, Thin Or Thick, Dry Or Oily, Thanks To The Electrostatic Charge That Guarantees A Perfect Hold: Even When Passing The Fingers Through The Hair, They Stay In Place And The Hand Remains Perfectly Clean,

Top 10 hair building fibers Brands on Amazon

Here is the list of top-rated brands that were evaluated by PM.

Brand Count
Hair Illusion 4
Find Back 2
Kaal 2
Aliver 1
Elaimei 1
Elbbub 1
Moulis 1
Pephuca 1
Vzdsddef 1
Zentanmei 1

Top 10 hair building fibers Brands Pie Chart


We've carried out a comprehensive analysis of 8,214 reviews on hair building fibers, using our selection criteria to identify the best options in the hair care products. Our findings reveal that most customers typically select hair building fibers priced around $20.26, with top brands including boldify, toppik, shifakou, xfusion, get back gorgeous, luxe professional, minute hair, aliver and cgify and sevich

Our team of expert editors reviewed these high-quality items and handpicked the top 15 hair building fibers for your consideration. We've also done extensive research on numerous sellers, identifying the best ones in the hair care products category. These include boldify, amazon.com, tanluo shop, getbackgorgeous, -glitzglam-, minute hair, chenhao beauty, runway-ready-store and sevichtopbeauty and bigfly .

We are dedicated to assisting our users in finding the right fibers Products based on their needs, saving them considerable time when choosing which hair building fibers to buy. We take pride in the number of satisfied users we've helped through our thorough and insightful reviews.