Why hair weakens

Hair loss and weakening can have many causes: nutritional deficiencies (iron, zinc, biotin, B vitamins), chronic stress, hormonal changes (pregnancy, menopause), genetic factors, external aggressions (heat, UV, pollution) or certain medical treatments.

On average, we lose 50 to 100 hairs per day — this is normal. Beyond that, we speak of effluvium (excessive shedding), which requires attention. But before looking for a hair solution, it is essential to understand that hair is a living tissue nourished from within. This is why food supplements, by providing essential nutrients to the hair follicle, can play a significant role.

The active ingredients that truly matter

Given the abundance of products on the market, here are the active ingredients truly supported by scientific data for hair health:

Active Ingredient	Role for hair	Effective Dosage
Biotin (B8)	Keratin synthesis, strengthens the fiber	100-200% of NRVs (50-100 µg)
Zinc (bisglycinate)	Hair growth, scalp health	100-150% of NRVs (10-15 mg)
Hydrolyzed Keratin	Directly strengthens the hair fiber	500 mg / day
Marine Collagen	Amino acids for keratin synthesis	5-10 g / day (powder)
Vitamin B5	Reduces hair loss, nourishes the follicle	100% of NRVs (6 mg)
Vitamin B6	Protein metabolism, growth	100% of NRVs (1.4 mg)
Vitamin C	Antioxidant, collagen co-factor	100% of NRVs (80 mg)
Iron	Follicle oxygenation (if deficient)	On medical advice
Selenium	Bulb protection (antioxidant)	100% of NRVs (55 µg)

Biotin: the "hair vitamin" deciphered

Biotin (vitamin B8 or B7 depending on the country) is ubiquitous in hair supplements. It participates in the synthesis of keratin, the protein that makes up 95% of hair. In case of biotin deficiency — rare but real (pregnancy, unbalanced diet, certain medications) — supplementation effectively improves resistance and growth.

However, studies are clear: overdosing biotin beyond 200% of NRVs provides no additional benefit in healthy individuals. Brands that display 10,000% of NRVs are playing on a marketing effect, not on science. The very low cost of synthetic biotin explains this race to overdose.

Keratin, collagen and amino acids

Hydrolyzed keratin (in patented form such as Cynatine® HNS) directly provides the amino acids that constitute hair. Clinical studies show a reduction in hair loss and an improvement in shine after 90 days at 500 mg/day.

Marine collagen provides the amino acid precursors of keratin (glycine, proline, hydroxyproline). It is an ideal supplement after 35, when natural collagen production decreases. Read our complete guide to marine collagen →

Sulfur amino acids (L-cystine, L-methionine) are the building blocks of keratin. They thicken the hair fiber and accelerate growth.

Effective dosages: the real numbers

A key fact to remember: regular supplementation with biotin, zinc and sulfur amino acids can reduce hair loss by about 25% after 3 months of use. But the absolute condition is regularity: results are only visible after a minimum of 8 to 12 weeks.

Recommended course: 3 months minimum, ideally 6 months for a complete result on growth and volume. Courses can be renewed, with a break of 2 to 4 weeks between each cycle if desired.

Gummies, capsules or powder?

Format	Advantages	Limitations
Gummies	Pleasant, easy, encourages adherence	Contains sugar, sometimes limited dosages
Capsules	Precise dosages, sugar-free	Less pleasant, gelatin sometimes not kosher
Powder (collagen)	High dosages, rapid absorption	Requires preparation

The gummy format has exploded in recent years, and for good reason: a course that is enjoyable to take is a course that gets completed. Adherence (taking your supplement every day without forgetting) is the #1 success factor.

The 5 mistakes to avoid

1. Overdosing biotin — More is not better. 100-200% of NRVs is enough. Excess is eliminated through urine and can skew certain blood test results.

2. Combining several supplements — Risk of overdose of zinc, selenium or vitamin A. Choose ONE well-balanced formula.

3. Giving up too early — The hair cycle lasts 3 to 6 months. Results are not visible in 2 weeks. Patience is essential.

4. Neglecting diet — A supplement does not replace a diet rich in protein, iron, zinc and vitamins. It complements it.

5. Ignoring the cause — Sudden or massive hair loss can signal a hormonal problem, iron deficiency or significant stress. Consult a dermatologist or doctor if hair loss persists despite supplementation.

Hair supplements and kashrut

K-Vital Beauty Gummies: hair, skin, nails

Frequently Asked Questions

Are hair supplements suitable during pregnancy?

Some active ingredients like biotin and zinc are suitable, but it is imperative to consult your doctor or gynecologist before any supplementation during pregnancy or breastfeeding. K-Vital also offers adapted Women's Multivitamin Gummies.

Can I take a hair supplement and magnesium at the same time?

Yes, both are compatible. Magnesium contributes to energy metabolism and fatigue reduction, which indirectly supports hair health. Read our guide on magnesium bisglycinate →

Do hair gummies make you gain weight?

No. A beauty gummy generally provides 5 to 10 kcal — a completely negligible amount, even at 2 gummies per day.