KeraNew is an oral supplement used to promote healthy hair, sold by a brand called Kintsugi. The brand claims that their supplement can cause hair that “looks fuller, healthier and more youthful.”
But does KeraNew contain research-backed ingredients for improving hair quality? Does it contain any unhealthy ingredients? Why do we take issue with some of the health claims on the brand's website? And is KeraNew better or worse than popular hair quality supplements like Nature's Bounty Hair Growth?
In this article we’ll answer all of these questions and more, as we analyze the ingredients in KeraNew to give our take on whether or not it's likely to improve hair quality, and whether or not it's healthy.
We’ll also highlight some questionable health claims on the KeraNew website that the brand has since removed, and compare KeraNew to other popular hair quality products to pick our winners (and losers).
Key takeaways:
- Contains some active ingredients shown to be effective
- Contains a relatively high vitamin D dose
- Brand removed questionable claims we called out
- We do not currently recommend KeraNew
Ingredient Analysis
Keranew contains a vitamin and mineral blend, shown below:

image source: https://kintsugihair.com/product/keranew/
We haven’t come across any medical evidence that taking large doses of vitamins and minerals without a deficiency in those vitamins or minerals has any health benefits, or optimizes hair quality.
We find it highly concerning that KeraNew contains such a high dose of vitamin D (5,000 IU or 1,250% of the Daily Value) given that this is a fat-soluble vitamin.
A medical review published in the Frontiers in Endocrinology journal documented that daily vitamin D doses over 4,000 IU per day can cause chronic toxicity, and KeraNew is just one of many potential sources of vitamin D in an American consumer’s diet (which may include other supplements like multivitamins and fortified foods).
The remaining active ingredients, which are mostly botanicals, are shown below:

image source: https://kintsugihair.com/product/keranew/
Keratin was shown in a 2014 clinical trial to reduce hair loss, improve hair brightness and improve hair tensile strength at the same dose as is included in KeraNew.
Collagen is clinically shown to support skin health, as we documented in our NeoCell Collagen review article. This suggests that collagen may support scalp health, although we haven’t come across any medical studies suggesting it does at a dose as low as in KeraNew.
The remaining botanical active ingredients are included at very low doses (25 mg), and we can’t find research studies proving any of these ingredients to be effective at that dose.
To give a sense of how low a 25 mg is, consider the ingredient ashwagandha which is included at that dose. According to the USDA, one teaspoon of ashwagandha equals 3,000 mg. This means that the ashwagandha dose in KeraNew is 120 times less than one teaspoon of ashwagandha.
The inactive ingredients in KeraNew, shown below, should be safe and non-toxic:

image source: https://kintsugihair.com/product/keranew/
Overall, we consider KeraNew somewhat likely to improve hair quality and reduce hair loss given its effective dose of keratin.
We do not recommend this supplement overall as we are concerned about the vitamin D dose, and because we only consider one active ingredient in this formulation of 24 active ingredients to be effectively dosed based on our review of clinical studies.
Questionable Health Claims on Site
When we initially published this article, we called out a number of questionable and uncited health claims on the KeraNew website. The brand appears to have removed these claims since.
As shown below, the brand claimed that their hair supplement could “quickly give hair a youthful appearance:”

image source: https://kintsugihair.com/product/keranew/
We didn't understand how the brand could make specific health claims when this supplement with a proprietary formula didn't appear to be clinically tested. What was this claim based on?
The brand also claimed that horsetail powder could improve the appearance of thinning hair:

image source: https://kintsugihair.com/product/keranew/
No citation was provided for this claim, and we have not come across any medical studies suggesting that horsetail powder at the very low dose of 3 mg has that effect.
The KeraNew website suggested that hyaluronic acid created the conditions for healthy-looking hair:

image source: https://kintsugihair.com/product/keranew/
Again, no citation or proof was provided for this claim.
We recommend that consumers be extremely wary of purchasing supplements from brands that make specific health claims without providing any proof to back those claims.
KeraNew vs. Popular Hair Care Products
Here's how KeraNew compares to other popular hair quality enhancers in terms of potential efficacy and healthiness, in our opinion:
Allurium Hair Growth Serum
Contains research-backed, naturally-derived active ingredients like peppermint, which is clinically shown to cause hair growth.
No unhealthy additives, and one of the highest-quality hair growth formulations we've reviewed to date on Illuminate Health.
Winner: Allurium Hair Growth Serum
Weem Hair Gummies
Contains no active ingredients we consider effectively-dosed for hair growth, as we documented in our Weem Hair Gummies reviews article.
Also contains inactive ingredients we consider to be unhealthy.
KeraNew has the advantage from both a potential efficacy and health perspective.
Winner: KeraNew
Nature's Bounty Hair Growth
Inferior formulation from a potential efficacy standpoint.
We consider KeraNew more likely to be effective.
Winner: KeraNew
Our Clean Hair Care Picks

Ritual HyaCera is our top hair growth supplement.
This supplement contains wheat oil extract, and a 2024 clinical trial reported that a wheat lipid complex had "a reducing effect on hair shedding and a stimulating effect on hair reappearance and growth."
MBG Omega-3 Potency+ is our top hair thickness pick.
Supplementation with omega-3 fats and antioxidants is clinically shown to improve hair density, and MBG's supplement contains both.
Both of the products recommended in this section are free of ingredients we consider to be unhealthy.
KeraNew Pros and Cons
Pros:
- Contains effective keratin dose
- May improve hair quality
- May improve hair thickness
- Non-toxic inactive ingredients
- Better formulation than some competitors
Cons:
- Contains vitamin D dose more than 10x the Daily Value
- Botanical ingredients may be underdosed
- Brand makes questionable and uncited health claims
- Doesn’t appear clinically tested