Nourkrin Hair Growth: Does It Work, and How Does It Compare With Viviscal?
Medical Director Dr Sin Yong explains what the trials of Nourkrin and Viviscal show and do not show, how supplements compare with medicine, and where home care fits in a hair loss plan at IN Eternity Clinic.
WhatsApp to Enquire →Key facts ↓Nourkrin, a marine-derived proteoglycan supplement, has small placebo-controlled trials suggesting it may reduce shedding and support hair growth, but most come from the same research group and independent replication is limited. Viviscal has a similar evidence base. Supplements can help alongside treatment, mainly for shedding or a proven deficiency; they do not replace medicine for pattern hair loss. See hair loss treatment.
- Nourkrin trial: in a randomised, double-blind trial of 55 people with hair loss of different causes, Nourkrin showed a significant effect on hair growth over six months, with no side effects reported [1].
- The theory: Nourkrin is described as “proteoglycan replacement therapy” with a marine extract (Marilex); the concept comes largely from the same research group that ran its trials [1][2].
- Viviscal: in a six-month randomised trial in women with self-perceived thinning, the supplement group gained more terminal hairs and hair diameter than the placebo group [3].
- Pooled data: a 2026 meta-analysis of 14 studies (967 people) found better hair-cycle measures with supplements, but no significant difference in total hair count (p = 0.06) [5].
- Biotin: taking 10 mg of biotin a day for a week distorted results in 9 of 23 biotin-based blood tests, including thyroid tests [7].
What are Nourkrin and Viviscal?
Nourkrin is an oral hair supplement made by Pharma Medico in Denmark. Its key ingredient is a marine-derived extract containing specific proteoglycans, branded Marilex. Proteoglycans such as versican and decorin help regulate the hair cycle, and the authors behind the product propose that a shortfall of them shortens the growth phase and contributes to pattern hair loss and shedding, which they call “follicular hypoglycania”. Supplementing them is described as proteoglycan replacement therapy [2]. It is an interesting idea, but it is a hypothesis proposed mainly by the same group that studies the product.
Viviscal is another oral hair supplement, built around a marine-protein complex with vitamins and minerals, according to its maker; Viviscal Pro is one of its product lines. Neither Nourkrin nor Viviscal acts on DHT, the hormone behind pattern hair loss, and both are sold as supplements rather than medicines, so they are not assessed by regulators for whether they work.
Does Nourkrin work? What the trials show
The main Nourkrin trial was randomised, double-blind and placebo-controlled. Fifty-five people with hair loss of different causes took the supplement or a placebo for six months; objective assessments showed a significant positive effect on hair growth, an open six-month extension suggested further improvement, and no side effects were reported [1]. The limits matter: the trial was small, mixed several causes of hair loss together, and its abstract does not give the size of the effect in hairs per square centimetre. Most published Nourkrin trials share the same lead author, and independent replication is limited.
Viviscal’s evidence is similar in scale. In a six-month randomised, double-blind trial in women aged 21 to 75 with self-perceived thinning hair, run at two private practices, the supplement group gained significantly more terminal hairs and hair diameter at 90 and 180 days than the placebo group, with no adverse events [3]. “Self-perceived thinning” is not a diagnosis, so it is unclear which causes of hair loss were included.
Reviews put this in context. A 2023 systematic review of 30 studies, 17 of them randomised trials, found that the higher-quality evidence suggested potential benefit for several products, including Viviscal and Nourkrin, with rare and mild side effects, and called for larger trials against active treatments [4]. A 2026 meta-analysis of 14 studies with 967 participants, covering eight commercial supplements including both, found better hair-cycle measures than placebo, such as a higher density of growing hairs, but no significant difference in total hair count (p = 0.06), and concluded that more rigorous, independent research is needed [5]. A fair summary is a plausible, modest benefit, especially for shedding, that varies between people.
Nourkrin vs Viviscal vs prescription treatment
| Nourkrin | Viviscal | Topical minoxidil (a medicine) | |
|---|---|---|---|
| What it is | Marine-derived proteoglycan extract (Marilex) [2] | Marine-protein complex with vitamins and minerals, per its maker | Medicine that lengthens the growth phase |
| Main trials | Small placebo-controlled trials, largely one research group [1] | Small placebo-controlled trials in women with self-perceived thinning [3] | Many randomised trials, including a Cochrane review in women |
| What it may do | Reduce shedding; modest support for growth | Increase terminal hair counts in trials | Regrowth in pattern hair loss in men and women |
| Acts on DHT? | No | No | No; works independently of DHT |
| Trial length | Six to twelve months | Three to six months | Judged at three to six months |
| Main cautions | Fish or shellfish allergy; check the label | Fish or shellfish allergy; check the label for biotin | Scalp irritation, early shedding, pregnancy |
For pattern hair loss, supplements are an add-on at most. They do not lower DHT or lengthen the growth phase the way prescription medicines do; see minoxidil: oral vs topical and anti-hair-loss medications.
Hair thinning causes: when do supplements make sense?
Thinning hair has several common causes, and they often overlap: pattern (androgenetic) hair loss; shedding two to three months after illness, childbirth, crash dieting or stress (telogen effluvium); low iron stores; thyroid disease; tight hairstyles; and, less often, scarring conditions of the scalp that need a dermatologist. Supplements address only some of these.
A review of vitamins and minerals in hair loss concluded that micronutrients such as iron, zinc and vitamin D play a real but not fully understood role in the hair cycle, that a deficiency may be a modifiable risk factor, and that large placebo-controlled trials in people with proven deficiency are still needed [6]. In practice, supplements make most sense where a blood test shows something low, or as support during a shedding phase. Where the cause is pattern hair loss, they are not enough on their own. See postpartum hair loss, oily scalp and hair loss and when to see a hair loss doctor.
Are hair growth supplements safe?
In the trials, side effects were rare and mild [4]. The more practical risk is with blood tests. Many hair supplements contain biotin, and biotin interferes with laboratory tests that use a biotin and streptavidin system. In a study of healthy adults taking 10 mg of biotin a day for a week, 9 of 23 such tests gave misleading results, some falsely high and some falsely low, including thyroid hormone tests [7]. A falsely abnormal thyroid result in someone being checked for hair loss can send the investigation the wrong way.
Tell your doctor and the laboratory which supplements you take; you may be advised to pause biotin for a few days before blood tests. Check the label if you have a fish or shellfish allergy, since both Nourkrin and Viviscal use marine ingredients. Stacking several hair products can multiply doses of the same vitamins, so bring the labels to your appointment. In pregnancy and while breastfeeding, ask before starting any supplement.
Where do supplements fit at IN Eternity Clinic?
The cause is assessed first: history, trichoscopy, standardised photographs and blood tests such as ferritin and thyroid function where indicated. A supplement is not a substitute for that step, because low iron, thyroid disease and pattern hair loss each need different treatment.
At IN Eternity Clinic, Nourkrin may be suggested as home care alongside in-clinic treatment. In-clinic options include H2LT laser, Regenera Activa and 1540 nm laser, with prescription medicine where suitable, and progress is reviewed against photographs at about three, six and twelve months. Results vary between people, and suitability is decided at an in-person assessment with Dr Sin Yong. If thinning keeps progressing on supplements alone, that is a reason to be assessed. See hair loss treatment in Singapore.
What Dr Sin Yong looks for
- Whether the thinning is pattern loss, diffuse shedding, patches or a mix.
- When it started, and any illness, childbirth, crash diet or stress two to three months before.
- Iron, thyroid and vitamin D results, and whether a deficiency explains the shedding.
- Supplements already taken, including biotin, and their doses.
- Signs of scalp inflammation or scarring that need a different kind of care.
General clinical observations used at consultation; they describe what is checked, not any individual result.
Frequently asked questions
What is Nourkrin?
Nourkrin is an oral hair supplement containing a marine-derived extract with specific proteoglycans, branded Marilex, made by a Danish company. It is described as proteoglycan replacement therapy, based on the idea that these molecules help regulate the hair growth cycle. It is a supplement, not a medicine, and does not act on hormones.
Does Nourkrin really work for hair growth?
Small placebo-controlled trials suggest it may reduce shedding and support growth: in one six-month trial of 55 people, hair growth improved significantly compared with placebo. Most trials come from the same research group and are small, so the benefit is plausible but modest and needs independent confirmation. Results vary between people.
Is Viviscal Pro better than Nourkrin?
No head-to-head trial has compared them, so neither can be said to be better. Both have small placebo-controlled trials showing benefit, and a 2023 systematic review placed both among the supplements with the stronger evidence. Finding the cause of the thinning matters more, because it decides whether any supplement is worthwhile.
Can I buy hair supplements in Singapore without seeing a doctor?
Yes, hair supplements are sold over the counter in Singapore. That makes it easy to start one before the cause is known. If thinning is progressing, sudden or patchy, or comes with fatigue, irregular periods or scalp symptoms, an assessment is worth doing first, because low iron, thyroid disease and pattern hair loss each need different treatment.
How long do hair growth supplements take to work?
Trials ran for three to twelve months, and hair grows slowly, so any change is judged after at least three months and more fairly at six. Taking a supplement for a few weeks and stopping tells you very little. Photographs taken in the same light help more than the mirror.
Do hair supplements affect blood tests?
Biotin can. In a study of healthy adults taking 10 mg a day, 9 of 23 biotin-based laboratory tests gave misleading results, including thyroid tests. Many hair supplements contain biotin, so tell your doctor and the laboratory what you take; you may be advised to pause it before blood tests.
What causes hair thinning in women?
Common causes are female pattern hair loss, shedding a few months after illness, childbirth, crash dieting or stress, low iron stores and thyroid disease, and several can occur together. Blood tests and a scalp examination separate them, and the right treatment depends on which is present.
Book an assessment
IN Eternity Clinic, 9 Scotts Road, #12-01 Pacific Plaza, Singapore 228210. By appointment with Medical Director Dr Sin Yong. Monday to Saturday, 11am to 8pm. WhatsApp or call +65 8815 3008. At IN Eternity Clinic a consultation fee applies, and it is waived if you go ahead with any medical treatment; the fee is S$120.
International KOL — CLASSYS · HIRONIC · DEKA · ALMA · FOTONA · LUTRONIC
References
- Thom E. Nourkrin: objective and subjective effects and tolerability in persons with hair loss. J Int Med Res 2006;34(5):514-519. doi:10.1177/147323000603400508
- Wadstein J, Thom E, Gadzhigoroeva A. Integral roles of specific proteoglycans in hair growth and hair loss: mechanisms behind the bioactivity of proteoglycan replacement therapy with Nourkrin® with Marilex® in pattern hair loss and telogen effluvium. Dermatol Res Pract 2020;2020:8125081. doi:10.1155/2020/8125081
- Ablon G, Dayan S. A randomized, double-blind, placebo-controlled, multi-center, extension trial evaluating the efficacy of a new oral supplement in women with self-perceived thinning hair. J Clin Aesthet Dermatol 2015;8(12):15-21. PMID:26705444
- Drake L, Reyes-Hadsall S, Martinez J, et al. Evaluation of the safety and effectiveness of nutritional supplements for treating hair loss: a systematic review. JAMA Dermatol 2023;159(1):79-86. doi:10.1001/jamadermatol.2022.4867
- Alanazi R, Alshammari S, Aldossari K, et al. Evaluating the effectiveness of commercial oral supplements for hair growth: a systematic review and meta-analysis. J Cosmet Dermatol 2026;25(4):e70817. doi:10.1111/jocd.70817
- Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. The role of vitamins and minerals in hair loss: a review. Dermatol Ther (Heidelb) 2019;9(1):51-70. doi:10.1007/s13555-018-0278-6
- Li D, Radulescu A, Shrestha RT, et al. Association of biotin ingestion with performance of hormone and nonhormone assays in healthy adults. JAMA 2017;318(12):1150-1160. doi:10.1001/jama.2017.13705
These sources describe mechanisms and general evidence. They are not a promise of any individual result; suitability is decided at an in-person assessment.