PCOS Causes: Why PCOS develops

This article is part of: PCOS: The Guide to Causes, Symptoms, and Treatment

PCOS has no single cause. It arises from the interplay of genetics, insulin resistance, androgen excess, and environment. This guide honestly explains the mechanisms and shows what you can influence yourself.

Key takeaways

PCOS is multifactorial: genetic predisposition, insulin resistance, androgen excess, and environmental factors reinforce each other. It is not a self-inflicted disease. Genes and early imprinting cannot be changed, but insulin sensitivity and stress are effective levers.

Guide Part of our PCOS Guide: everything important at a glance →

PCOS is one of the most common hormonal disorders in women, yet many half-truths surround the question of where it actually comes from. The honest answer: There is no single cause. PCOS arises from an interplay of several factors. This article categorizes what research currently knows about the causes, without oversimplifying.

This is more than academic: those who understand the mechanisms behind PCOS can better comprehend why certain approaches, such as insulin management or stress reduction, are helpful at all. One thing up front: PCOS is not something you brought upon yourself through your lifestyle. The predisposition lies deeper.

PCOS has no single cause

For a long time, PCOS was primarily explained by the ovaries. Today it is clear: it is a complex disorder involving several body systems, especially the hormonal and metabolic balance. Research describes PCOS as multifactorial, meaning that genetic predispositions, metabolic processes, and environmental influences come together.¹

These factors do not exist in isolation, but reinforce each other. A genetic predisposition can promote insulin resistance, insulin resistance drives up androgens, and androgens in turn disrupt ovulation. This creates the typical picture of an irregular cycle, elevated male hormones, and metabolic issues.

Precisely this chain of events also explains why PCOS looks somewhat different in every woman. In one, metabolism is in the foreground, in another, androgen symptoms such as acne and increased hair growth, and in a third, primarily the irregular cycle. It is the same underlying condition, but with different weighting of the contributing factors. That's why there isn't one PCOS experience and not one solution.

PCOS is not a self-inflicted illness, but a complex predisposition.

Factor 1: Genetic predisposition

PCOS often runs in families. If a mother or sister is affected, the risk for an individual is significantly increased. Studies have identified several gene variants associated with PCOS that affect, among other things, hormone regulation and insulin metabolism.²

Important to note: There is no single PCOS gene. Rather, many small genetic influences collectively contribute to the predisposition. These genes alone do not determine whether someone develops PCOS, but they lay a foundation upon which other factors can act.

In addition to the pure gene sequence, epigenetics also plays a role. This refers to how strongly individual genes are read, which can be altered by environmental influences without changing the DNA itself. Such epigenetic imprints are an active field of research and could explain why PCOS can vary greatly even within the same family.

Factor 2: Insulin Resistance

One of the most important mechanisms in PCOS is insulin resistance. In this condition, cells are less sensitive to insulin, so the body produces more of it to keep blood sugar stable. Many women with PCOS are affected by this, including slender women.

Elevated insulin has a direct hormonal consequence: it stimulates the ovaries to produce more androgens and simultaneously reduces a transport protein in the blood, making even more free testosterone available. Thus, a metabolic issue becomes a hormonal one. This is precisely why improving insulin sensitivity is one of the most effective starting points for PCOS.

Insulin resistance is not necessarily the primary cause, but often part of a vicious cycle. Many women have a predisposition that is exacerbated by factors such as lack of exercise, sleep problems, or stress. This explains why lifestyle measures can be effective here, without PCOS becoming a lifestyle disease.

It is interesting that insulin resistance in PCOS often exists independently of body weight. Even slender women with PCOS can be affected, which shows that it is an inherent characteristic of the predisposition and not just a consequence of overweight. This is an important point, as it refutes the common assumption that PCOS is simply a weight problem.

Factor 3: Androgen Excess

The eponymous characteristic of PCOS is an excess of androgens, i.e., hormones often referred to as male but also present in the female body. This excess is responsible for many of the visible symptoms, such as increased body hair, acne, or hair loss on the head.

Androgens come from two sources: the ovaries and the adrenal glands. High insulin primarily boosts production in the ovaries. At the same time, androgen excess disrupts the maturation of the follicles, which makes ovulation difficult and leads to irregular cycles. Thus, insulin, androgens, and menstrual cycle disorders interact and form the core of PCOS.

Factor 4: Environment and Early Programming

Environmental factors are also discussed as influences. These include hormonally active substances from the environment, so-called endocrine disruptors, as well as influences that act even before birth. Research suggests that the hormonal environment in the womb can contribute to later predisposition.

These connections are the subject of current research and are not yet fully understood. What is clear is that these are influencing factors, not sole triggers. They fit into the multifactorial picture and help explain why PCOS can manifest so differently.

What can be practically learned from this: Even if not every environmental influence can be avoided, it is worth keeping the big picture in mind. A healthy foundation of nutrition, exercise, sleep, and conscious stress management affects several of these factors simultaneously and is therefore the most sensible leverage, rather than overestimating individual environmental sources.

Cycle+ Formula for your cycle balance

Cycle+ Formula, with Myo-Inositol and other active ingredients, precisely addresses the key mechanisms involved in PCOS, above all insulin metabolism. Clinically dosed and medically developed.

€75,00

Discover Cycle+ Formula

A Hypothesis: Does PCOS have an Evolutionary Background?

In science, there is also discussion about whether the genetic predispositions behind PCOS might have offered advantages in the past. The idea: traits such as efficient energy metabolism or higher androgen levels could have been beneficial during times of food scarcity or high physical exertion, for example, for energy storage or muscle strength.

It's important to frame this correctly: this is a hypothesis, not a confirmed explanation. It is interesting because it shows that the predispositions behind PCOS are not simply a defect, but could have had a different meaning in a different context. This does not change current treatment, but it can help to understand PCOS less as a defect and more as a predisposition that manifests unfavorably in our modern lifestyle.

This perspective does not replace what we concretely know about the mechanisms. It is a supplementary viewpoint that clearly shows how complex the question of origin truly is.

However, such hypotheses should not be overinterpreted. From the idea that PCOS predispositions might have been useful in the past, no concrete treatment approach can be derived, and it does not change the fact that the symptoms can be distressing today and require treatment. The value of this perspective lies primarily in understanding and reassurance, not in a therapeutic consequence.

Why Understanding the Causes Helps

When you know the causes, the common recommendations suddenly make sense. That insulin management through diet, exercise, and potentially agents like myo-inositol is so central is directly due to the role of insulin resistance. That stress reduction helps is related to the stress axis and its influence on androgens and insulin.

Understanding also relieves pressure: PCOS is not a result of a lack of discipline. It is a predisposition that can, however, be managed well. Symptoms can be significantly improved in many women if the right levers are pulled, instead of blaming oneself.

What You Can Influence Yourself

You cannot change your genes and early imprinting, but several important levers are in your hands. The crucial idea here: you don't have to fight the predisposition, but rather relieve the mechanisms through which the symptoms are amplified. The best-supported approaches are:

Improve insulin sensitivity:Through a balanced, fiber-rich, and protein-rich diet, regular exercise, and especially strength training.
Regulate stress:Since the stress axis influences androgens and insulin, sleep, recovery, and relaxation help.
Ensure micronutrient foundation:Certain nutrients and active ingredients like myo-inositol are discussed as supportive in PCOS.
Know your values:Diagnostics provide clarity about which factors are paramount for you.

Do you want to understand the causes of your PCOS? We're here to listen.

The first 15 minutes with one of our doctors are free of charge. We assess your symptoms and values and show you which factors are most important for you and what you can do.

Secure your free initial consultation

Conclusion

PCOS has no single cause. It arises from the interaction of genetic predisposition, insulin resistance, androgen excess, and environmental factors, which mutually reinforce each other. This makes the condition complex, but also understandable once you know the individual components.

The most important message: PCOS is not a self-inflicted condition. You cannot eliminate the predisposition, but you can address the crucial levers, especially insulin and stress. If you want to know which factors are particularly pronounced in your case, a medical examination and diagnosis is the best first step.

And understanding the causes often changes one's perspective on their own diagnosis. Instead of seeing PCOS as something you did wrong, it becomes a predisposition that can be actively managed. Precisely this attitude, informed and without self-reproach, is the best foundation for long-term change.

Frequent Questions about the Causes of PCOS

What is the main cause of PCOS?

There isn't one single main cause. PCOS develops multifactorially, meaning it results from the interplay of several factors: a genetic predisposition, frequent insulin resistance, an excess of androgens, and environmental influences. These factors reinforce each other, for example, when high insulin drives androgens, and these disrupt ovulation. Precisely for this reason, there isn't one single treatment, but rather an approach that addresses multiple levers.

Is PCOS hereditary?

A predisposition to PCOS is hereditary. The condition frequently runs in families, and if a mother or sister is affected, one's own risk is increased. However, what is inherited is not PCOS directly, but a genetic predisposition through many small influences. Whether and how strongly symptoms manifest also depends on factors such as insulin metabolism, stress, and lifestyle, some of which can be influenced.

Ist PCOS selbst verschuldet oder durch den Lebensstil verursacht?

Nein. PCOS ist keine selbstverschuldete Erkrankung und kein Resultat mangelnder Disziplin. Die Grundlage ist eine genetische und hormonell-metabolische Veranlagung, die tiefer liegt als der Lebensstil. Lebensstilfaktoren wie Bewegung, Ernaehrung und Stress koennen die Auspraegung der Symptome mit beeinflussen, sind aber nicht die Ursache. Diese Unterscheidung ist wichtig, weil sie unnoetige Schuldgefuehle nimmt und den Blick auf das richtet, was tatsaechlich hilft.

Kann man PCOS heilen, wenn man die Ursache kennt?

PCOS gilt derzeit als nicht heilbar, aber als gut behandelbar. Da die Veranlagung genetisch verankert ist, laesst sie sich nicht entfernen. Sehr wohl lassen sich aber die Mechanismen beeinflussen, die die Symptome antreiben, vor allem die Insulinresistenz und die Stressachse. Viele Frauen erreichen dadurch regelmaessigere Zyklen, weniger Androgensymptome und ein besseres Wohlbefinden. Das Verstaendnis der Ursachen hilft dabei, gezielt an den richtigen Stellen anzusetzen.

Scientific Sources

Stener-Victorin, E., et al. (2024). Polycystic ovary syndrome: pathophysiology and therapeutic opportunities. Nature Reviews Endocrinology. doi:10.1038/s41574-024-00956-2
Day, F., et al. (2018). Large-scale genome-wide meta-analysis of polycystic ovary syndrome suggests shared genetic architecture. PLoS Genetics, 14(12), e1007813. doi:10.1371/journal.pgen.1007813
Diamanti-Kandarakis, E., & Dunaif, A. (2012). Insulin resistance and the polycystic ovary syndrome revisited. Endocrine Reviews, 33(6), 981-1030. doi:10.1210/er.2011-1034
Escobar-Morreale, H. F. (2018). Polycystic ovary syndrome: definition, etiology, diagnosis and treatment. Nature Reviews Endocrinology, 14(5), 270-284. doi:10.1038/nrendo.2018.24
Dumesic, D. A., et al. (2015). Scientific statement on the diagnostic criteria, epidemiology, pathophysiology, and molecular genetics of PCOS. Endocrine Reviews, 36(5), 487-525. doi:10.1210/er.2015-1018
Parker, J., et al. (2022). An evolutionary model of PCOS: a unifying hypothesis. International Journal of Molecular Sciences, 23(3), 1336. doi:10.3390/ijms23031336

About the Author

Lisa Maria Emmer

Physician & Medical Director · Hormonic

Lisa Maria Emmer is co-founder and medical director at Hormonic. She supports women with hormonal problems every day and specializes in cycle health, PCOS, and menopause.

Note: This article is based on current scientific studies and reviews (as of 2026). It is for informational purposes only and does not replace professional medical advice, diagnosis, or treatment.

PCOS: Der Guide zu Ursachen, Symptomen und Behandlung

PCOSMay 27, 20267 min read

PCOS: The Guide to Causes, Symptoms, and Treatment

PCOS, now also known as PMOS, affects 8 to 13 percent of women of reproductive age. This guide explains causes, symptoms, diagnosis, and what the evidence says about lifestyle, inositol, and micron...

Ruhige selbstbewusste Frau in hellem Raum, Thema PCOS Symptome

PCOSDec 12, 20258 min read

Understanding PCOS symptoms: A comparison of the 4 PCOS types

PCOS symptoms are varied – this article explains the four PCOS types in detail, shows typical signs and helps you to better identify your type.

Frau liegt erschöpft im Bett, Symbolbild für Müdigkeit bei Insulinresistenz

StoffwechselApr 10, 20268 min read

Insulin Resistance in Women: Causes, Symptoms & What Helps

Insulin resistance affects many women, but often remains undetected for a long time. Learn how hormones and metabolism are connected and what can specifically help with insulin resistance.

Cart

PCOS Causes: Why PCOS develops and what's behind it