Loss of libido mostly due to increased MAO levels
Professor Graham asks why the effects of the pill on women’s sexuality have been neglected.1 She believes that, although an association between pill use and impaired sexual functioning has been considered since the pill was first introduced, remarkably little research has investigated this. In fact, depressive mood changes, including loss of libido, have always been main reasons (along with headaches. weight gain, sore breasts and bleeding) for first year discontinuation of hormonal contraception and we did discover a crucial biochemical mechanism for loss of libido during the early 1960s.2-7
The London Council for the Investigation of Fertility Control prospective pill trial compared daily effects (including sexual activity) before, during and after pill use. Some women even believed that inducing loss of libido was how the pill was meant to work to prevent them becoming pregnant! We found that the first-year incidence of depressive mood changes increased, with increasing progestogenic potency, from 10% to 44% using lower oestrogen dose combinations. The highest incidence of depressive mood changes occurred with strongly progestogenic pills which produced high monoamine oxidase activity for most of the cycle. This is a pathological extension of a physiological effect because endometrial monoamine oxidase activity increases six-fold in the human menstrual cycle from <4000 cpm/mg in proliferative and early secretory phases to 10,000-21,000 cpm/mg in the late secretory phase.4,5 This 6-fold increase coincides with the timing of the depressive premenstrual syndrome (PMS). All OCs mostly act like progesterone which increases monoamine oxidase levels while oestrogens lower levels. Monoamine oxidase inhibitor drugs (MAOIs) were found coincidentally to be anti-depressants in the 1950s. The enzyme monoamine oxidase inactivates, or stores, monoamines which control mood and behaviour and vascular reactivity and similar increases are found in the blood and brain.6,7 This effect will be continuous with progestogen only contraceptives which need to be potently progestogenic to prevent pregnancy. It should be alarming that in 2014 a National Health Service mental health survey found that 26% of young women aged 16 to 24 years in England had mental health problems compared with 9.1% of young men.8
Hormonal contraceptives can cause mineral imbalance by lowering zinc and raising copper levels.9 Oysters have a high zinc content and are a famous aphrodisiac whereas alcoholic drinks increase zinc excretion and cause loss of libido.
Unfortunately for girls and women there has been a cover up about the true dangers of hormonal contraception which has been aided by flawed epidemiological studies and lack of never-ever user controls. Our 1960s discoveries of underlying “side effect” mechanisms and changes to blood vessels have been mostly ignored. This assault on women’s rights has been justified by overriding concern about the exponential growth of the world’s population. www.harmfromhormones.co.uk
1 Graham C A. The pill and women’s sexuality. BMJ 2019;364:l335
2 Mears E, Grant ECG. "Anovlar" as an oral contraceptive. BMJ 1962; 2: 75-79.
3 Grant ECG. Hormone balance of oral contraceptives. BJOG 1967;74:908-18.
4 Grant ECG, Mears E. Mental effects of oral contraceptives. Lancet 1967;1:945-46
5 Grant ECG, Pryse Davies J. Effect of oral contraceptives on depressive mood changes and on endometrial monoamine oxidase and phosphatases. BMJ 1968;3:777-780.
6 Southgate J, Grant ECG, Pollard W, Pryse Davies J, Sandler M. Cyclical variations in endometrial monoamine oxidase: Correlations of histochemical and quantitative biochemical assays. Biochemical Pharmacology 1968;17:21-26.
7 Grant EC. Hormonal Contraception and Its Association With Depression.
JAMA Psychiatry. 2017 Mar 1;74(3):301-302. doi: 10.1001/jamapsychiatry.2016.3701.
8 Digital NHS. Mental Health and Wellbeing in England: Adult Psychiatric Morbidity Survey 2014. September 2016.
9 Grant ECG. The pill, hormone replacement therapy, vascular and mood over-reactivity, and mineral imbalance. J Nutr Environ Med 1998;8:105-116.
Competing interests: No competing interests