What are the downsides of the contraceptive pill?
The contraceptive pill has been a fixture of women's healthcare for over sixty years. It is effective at preventing pregnancy and is widely prescribed for managing menstrual-related symptoms including pain, heavy bleeding, and acne. But are women ever fully informed about what it does to their body beyond preventing ovulation?
In my clinical experience, the answer is often no. This post is not an argument against the pill as a contraceptive choice - that is a personal decision and one I respect entirely. But it is an argument for informed consent. Women deserve to understand what the pill does and does not do, so they can make genuinely informed decisions about their own health.
The pill does not regulate your hormones - it suppresses them
This is the point I find myself making most often in clinic, and it bears repeating clearly: the pill does not regulate your periods. It suppresses your natural hormonal cycle entirely.The combined pill works by introducing synthetic versions of oestrogen and progesterone (progestin) that switch off the body's own hormone production. Ovulation is suppressed. The natural monthly rhythm of oestrogen and progesterone - which influences mood, metabolism, bone health, cardiovascular function, libido, and cognition - is replaced by a flat, synthetic hormone exposure with no cyclical variation.The bleed that occurs during the pill-free interval is not a real period. It is a withdrawal bleed caused by stopping the synthetic hormones temporarily. It tells you nothing about your underlying hormonal or menstrual health.This matters because women who go on the pill in their teens or twenties to manage symptoms like acne, painful periods, or mood changes are not treating those issues - they are masking them. The underlying drivers remain unaddressed. When the pill is eventually stopped, the symptoms frequently return, sometimes more intensely than before. This is also the mechanism behind post-pill PCOS, which I have written about separately.
Nutrient depletion
The pill depletes a range of essential nutrients, and this is one of its most clinically significant and underreported effects.Research consistently shows that women taking the combined pill have lower levels of B vitamins (particularly B6, B12, and folate), magnesium, zinc, selenium, and vitamin C compared to women not taking it. The mechanisms include increased urinary excretion, altered gut absorption, and changes in the liver's processing demands.These are not minor micronutrients. B6 is essential for serotonin and dopamine synthesis - deficiency directly contributes to low mood, anxiety, and PMS-like symptoms. Folate is critical for cell division and is particularly important for women who may become pregnant after stopping the pill. Magnesium deficiency is associated with anxiety, poor sleep, muscle tension, and headaches. Zinc is essential for immune function, skin health, and ovulation.Many of the side effects commonly attributed to the pill - low mood, fatigue, reduced libido, recurrent infections - may be partly driven by these nutrient depletions rather than the hormones themselves. Women on the pill long-term should consider monitoring their nutrient status and supplementing accordingly, ideally with the guidance of a registered practitioner.
Disruption to the gut microbiome
The gut microbiome is increasingly recognised as central to overall health, influencing immunity, mood, digestion, and - crucially - hormone metabolism. The synthetic hormones in the pill alter the composition and diversity of gut bacteria, contributing to dysbiosis.This is relevant to hormonal health specifically because of the estrobolome - the collection of gut bacteria responsible for metabolising and clearing oestrogen from the body. When the microbiome is disrupted, oestrogen clearance is impaired and reabsorption increases, contributing to oestrogen dominance even after the pill is stopped.Gut dysbiosis associated with pill use can also worsen nutrient absorption, compounding the depletion issue discussed above, and is associated with increased intestinal permeability - the leaky gut connection that I have written about separately in relation to progesterone and hormonal balance.
Effects on mood and mental health
The relationship between the pill and mood is one of the most contested and underacknowledged areas in women's health. The research is mixed, but a large Danish cohort study following over a million women found that use of hormonal contraception was associated with a significantly increased risk of depression diagnosis and antidepressant prescription, particularly in adolescents.The mechanisms are not fully understood but are likely to involve the depletion of B6 (essential for serotonin synthesis), suppression of naturally occurring testosterone (which contributes to mood and motivation in women), and the removal of the cyclical hormonal variation that the brain has adapted to over a lifetime.Women who notice mood changes after starting the pill - particularly low mood, emotional blunting, or increased anxiety - should take those symptoms seriously and discuss them with their healthcare provider rather than assuming they are unrelated.
Effects on libido
Reduced libido is one of the most commonly reported side effects of the pill and one of the least openly discussed. It is caused by a combination of factors: the pill increases sex hormone binding globulin (SHBG), a protein that binds testosterone and renders it inactive. Since testosterone contributes to libido and arousal in women, elevated SHBG effectively reduces the amount of free testosterone available.In some women, SHBG levels remain elevated even after stopping the pill, which may explain persistent low libido post-pill.
The bigger picture
None of this means the pill is never the right choice. For many women it is an effective and appropriate option. But it should be prescribed alongside honest information about its systemic effects - not handed out as a first-line treatment for acne or painful periods without discussion of alternatives.There are well-evidenced nutritional and lifestyle approaches that address the root causes of hormonal symptoms including painful periods, heavy cycles, acne, and PMS. If you have been using the pill to manage these symptoms and want to understand what is actually driving them, that is exactly the kind of work I do with clients.
Book a free 20-minute consultation to find out how I can help, or explore my Women's Health Nutrition Packages.
