ENZYM ACHTER DE VORMING VAN DHT

5-alpha-reductase and hair loss

5-alpha-reductase is een enzym dat testosteron omzet in dihydrotestosteron (DHT). Die omzetting is normaal, maar kan bij erfelijk gevoelige haarzakjes bijdragen aan folliculaire miniaturisatie en geleidelijke patroonhaaruitval. Lees welke typen van het enzym bestaan, hoe de DHT-route werkt en wat dit wel en niet zegt over jouw haarverlies.

Man met erfelijke haarverdunning naast een medische visualisatie van DHT en haarzakjes

In brief

  • 5-alpha-reductase zet testosteron lokaal om in het krachtiger androgeen DHT.
  • De typen 1 en 2 komen in verschillende verhoudingen voor in huid, haarzakjes en andere weefsels.
  • DHT veroorzaakt niet automatisch haaruitval; erfelijke gevoeligheid van specifieke haarzakjes is bepalend.
  • Bij gevoelige haarzakjes kan de groeifase korter worden en kan ieder volgend haar fijner groeien.
  • Een bloedwaarde alleen kan niet aantonen of 5-alpha-reductase jouw haaruitval veroorzaakt.
Medische illustratie van 5-alpha-reductase dat testosteron omzet in DHT bij haarzakjes

BIOLOGICAL CONVERSION

What does 5-alpha-reductase do?

5-alpha-reductase is an enzyme that converts testosterone into dihydrotestosterone in various tissues, usually abbreviated as DHT. DHT binds more strongly to the androgen receptor than testosterone and can therefore produce a more potent local signal.

This conversion is part of the normal hormonal balance in both men and women. Its effect depends on the tissue, the enzyme activity present, and the cells’ sensitivity to androgens.

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TYPE 1 AND TYPE 2

What types of 5-alpha reductase are there?

For hair and the scalp, types 1 and 2 are particularly relevant. The enzyme types are encoded by different genes and are not found everywhere in the same proportions. Type 1 is found, among other places, in the skin and sebaceous glands; type 2 is present in various androgen-sensitive tissues and hair follicles.

Both types can contribute to the local formation of DHT. However, their presence alone does not indicate how much hair thinning someone will experience, because the inherited sensitivity of the hair follicles plays a decisive role.

Wetenschappelijke illustratie van de omzetting van testosteron naar DHT door 5-alpha-reductase
Vergelijking van een normaal en androgeengevoelig haarzakje

HEREDITARY PREDISPOSITION

Why do some hair follicles respond to DHT?

In androgenetic alopecia, certain hair follicles are genetically more sensitive to androgens. Locally formed DHT can bind to androgen receptors around the dermal papilla and influence growth signals.

Sensitivity varies by scalp area. Hair follicles at the hairline, crown, or central part may respond more strongly, while hair at the back and sides is often better preserved.

PROGRESSIVE PROCESS

How does follicular miniaturisation occur?

In sensitive hair follicles, the anagen growth phase can gradually become shorter. As a result, the hair has less time to build up length and thickness.

Over successive cycles, thick terminal hairs are replaced by shorter and finer hairs. The process is usually gradual and can lead to a more visible scalp without all the hair follicles disappearing immediately.

Opeenvolgende stadia van folliculaire miniaturisatie door DHT-gevoeligheid
Dermatoloog beoordeelt patroonhaaruitval met een dermatoscoop

DIAGNOSIS AND TREATMENT

How is this form of hair loss assessed?

A doctor assesses the pattern, progression, family history, and possible other causes. Dermoscopy can reveal variation in hair diameter and other signs of miniaturisation. A testosterone or DHT blood level is usually not sufficient for diagnosis.

Some medical treatments affect the 5-alpha-reductase/DHT pathway; others work through a different mechanism. The choice and safety should be discussed individually with a doctor. Food supplements do not inhibit 5-alpha-reductase and do not treat androgenetic alopecia.

View hair loss patterns in men

Belangrijk om te weten

5-alpha-reductase is een normaal lichaamseigen enzym. De aanwezigheid ervan betekent niet dat iemand alopecia androgenetica heeft. Diagnose berust op het patroon, de voorgeschiedenis en onderzoek van haar en hoofdhuid. Plotselinge diffuse uitval, scherp begrensde kale plekken, roodheid, schilfering of pijn passen niet vanzelfsprekend bij deze route en verdienen professionele beoordeling.

Read more about hair loss

Man met patroonhaaruitval naast een illustratie van DHT en haarzakjes

DHT AND HAIR LOSS

DHT and hair loss

Learn how DHT is formed and why only genetically sensitive hair follicles can miniaturize.

Read more →
Man en vrouw met typische patronen van alopecia androgenetica

HEREDITARY HAIR LOSS

Androgenetic alopecia

Learn how pattern hair loss develops, progresses, and is assessed in men and women.

Read more →
Man met haarverdunning naast een visualisatie van folliculaire miniaturisatie

BIOLOGICAL PROCESS

Follicular miniaturisation

Discover how hair follicles can produce increasingly finer hairs during successive growth cycles.

Read more →

Vragen over 5-alpha-reductase en haaruitval

What is 5-alpha reductase?

5-alpha-reductase is an enzyme naturally produced by the body that converts testosterone into dihydrotestosterone (DHT). The enzyme is found in various tissues, including the skin and hair follicles.

What is the difference between type 1 and type 2?

Type 1 and type 2 are encoded by different genes and occur in different tissues and proportions. Both can contribute to local DHT formation, but their precise role varies by tissue.

Does 5-alpha-reductase cause hair loss in everyone?

No. The enzyme is normally present. Follicles that are particularly genetically sensitive can respond to locally formed DHT with follicular miniaturisation.

Can a blood test measure enzyme activity in my scalp?

A standard blood test does not directly measure local enzyme activity in hair follicles. Normal hormone levels do not rule out androgenetic alopecia, and higher levels do not prove the diagnosis.

Should 5-alpha-reductase always be inhibited?

No. The appropriate approach depends on the diagnosis, health, sex, age, expectations, and possible side effects. Treatments that affect this pathway should be discussed with a doctor.

When is a professional assessment advisable?

Have gradual pattern thinning assessed when the hairline recedes, the crown becomes more visible, or the part widens. Rapid hair loss, bald patches, or scalp problems also warrant assessment.

FIND WHAT SUITS YOU

What support is suitable for hereditary hair thinning?

The TRIX Hair Check helps you better map out your pattern of hair loss and shows which TRIX Basic products may suit you. The Hair Check does not provide a medical diagnosis.

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