Do men need estrogen for their health?
Yes, men need oestrogen for strong bones, healthy blood vessels, and fertility. Both a deficiency and an excess are harmful, so it is a matter of finding the right balance.
Men produce oestrogen themselves, but not via the testes. Adipose tissue is the only relevant source: it converts testosterone into oestradiol (the active form of oestrogen). The more adipose tissue a man has, the more this conversion takes place.
For bones, oestrogen is at least as important in men as it is in women. Men with very low oestradiol levels have approximately 2.5 times the risk of a hip or vertebral fracture. Notably, testosterone itself has almost no direct relationship with bone mass. It appears to act almost exclusively through its conversion to oestrogen.
Testicular function and sperm production are also dependent on a proper oestrogen balance. Too little oestrogen can reduce fertility in men. At the same time, the reverse also holds: chronically elevated oestrogen levels have been linked to hormone-dependent cancers and immune problems.
Oestrogen receptors are also found in the walls of blood vessels in men. They play a role in vasodilation and blood pressure regulation, which creates a link with cardiovascular health. This relationship is for now associative: it is clearer that both high and low levels cause harm than what the precise mechanism is.
In short, oestrogen is not a minor consideration in men. It co-regulates bone health, the heart and blood vessels, metabolism, and reproduction. Both too little and too much is unfavourable; it is a matter of balance.
All claims are based on associational and probably causal research in humans (no large RCTs). Strength of evidence is moderate; for bones and fracture risk, the association is most robustly supported.
Do male hormones affect how quickly men age?
Declining testosterone measurably accelerates ageing of muscles, bones and sexual function, but the links to mood and skin are far less certain. Testosterone supplementation can relieve some symptoms, but always discuss the risk profile with your doctor before starting.
Does testosterone decline in men with age, and should you do something about it?
Testosterone really does decline in men with age. TRT is well supported only in men with established hypogonadism and symptoms, primarily for sexual function. If you have symptoms, always have the underlying cause investigated first.
Is testosterone important for women?
Testosterone is a physiologically relevant hormone for women, with the strongest evidence for sexual desire and sexual function. If you have symptoms consistent with low testosterone levels, it is worth discussing this with your doctor, including the choice of skin-based delivery.
Can estrogen cream help with urinary tract inflammation?
Locally applied oestrogen cream demonstrably reduces the risk of recurrent urinary tract infections in women after the menopause. Oestrogen pills do not help with this; discuss the cream with your doctor if you regularly suffer from bladder infections.
Can vaginal oestrogen therapy do more than simply relieve symptoms -- such as preventing urinary tract infections or even extending your life?
Vaginal oestrogen does more than relieve symptoms: it roughly halves the risk of recurrent urinary tract infections and reduces bladder symptoms. Whether it also extends life, nobody knows; that has never been studied.
Does using testosterone help if you are over 50, and can it be dangerous?
Testosterone can be worthwhile for men over 50 with a medically confirmed testosterone deficiency, but it is not a treatment for everyone who is getting older: the benefits are real, the risks are too, and a doctor must establish the indication.