In fertile men, new sperm cells are constantly created in the testicles. This process is triggered by the hormone testosterone. The goal of hormonal contraception research is to find a way of temporarily blocking the effects of testosterone so testicles stop producing healthy sperm cells.
However, this needs to be achieved without lowering testosterone levels to such an extent that it triggers side effects, such as a loss of sexual desire. One way of doing this is by giving men a synthetic version of testosterone, together with a hormone called progestogen. Progestogens are synthetic versions of a female sex hormone often found in female hormonal contraceptives, such as the progestogen-only pill. This approach stops the testes producing testosterone which, in most cases, prevents normal sperm production.
However, at the same time it keeps the amount of testosterone in the blood normal, preventing side effects. This is a very effective approach, but some men still carry on producing enough sperm to cause a pregnancy.
The reason why this happens is unknown, but it may be that some men carry on producing enough testosterone to continue to stimulate some sperm production. Research is now focusing on different combinations of synthetic testosterone and progestogens.
Several trials in different countries are looking at the effectiveness and long-term safety of hormonal contraceptives for men, including some phase III trials. Phase III trials are the last clinical trials carried out before a medicine is given a marketing licence.
An important disadvantage of using synthetic testosterone is that sperm production is suppressed at different rates in men of different ethnic origins. These differences may be due to genetic, dietary or environmental factors, but the exact reasons are unknown. Understanding the reasons may lead to new ways of providing effective contraception for all men of diverse ethnic backgrounds. Many of the non-hormonal methods of contraception currently being studied involve the vas deferens.
The vas deferens is the tube that sperm pass through on their way to the penis. This tube is cut during a vasectomy. One promising avenue of research is a technique called reversible inhibition of sperm under guidance RISUG.
While testosterone can affect the menstrual cycle, many people still bleed from time to time while using testosterone. Hormonal birth control can help prevent that. Certain hormonal birth control pills are often prescribed to treat acne, while others are used to treat heavy periods.
If you want to manage certain symptoms that are often treated with contraceptives but you want to avoid hormonal birth control , talk to a doctor. The side effects vary from person to person. They depend on the type of birth control you choose. For this reason, a doctor will take your blood pressure and ask about your medical history before prescribing any contraceptives. Fact: Testosterone often makes your period less regular and more sparse, but many people who take testosterone still menstruate.
Long-term use of testosterone usually stops menstruation. For example, people who are assigned male at birth but identify as something other than male might consider feminizing hormone therapy. The process of hormonal transitioning is complex. It requires specialized medication and the supervision of an expert.
According to Mayo Clinic , there are a few potential side effects of feminizing hormone therapy. Hormone therapy can be riskier for people with certain conditions, such as people with a history of hormone-sensitive cancer like prostate cancer or high blood pressure.
Myth: Estrogen-based hormonal birth control is a feminizing treatment that can form a type of hormone therapy for people assigned male at birth. People who are assigned female at birth — including transgender men taking testosterone — can take hormonal birth control pills safely.
Her writing covers issues relating to social justice, cannabis, and health. Initial "phase one" safety tests with 40 men looked promising, they told the Endocrine meeting in New Orleans. And among those taking the androgen-based drug, levels of hormones required for sperm production dropped greatly compared with placebo, returning to normal after the trial. Five men on the pill reported mildly decreased sex drive - and two described mild erectile dysfunction - but sexual activity was not decreased, no participant stopped taking it because of side-effects and all passed safety tests.
The researchers behind the work, Prof Christina Wang and colleagues, are excited but cautious about the findings. But bigger, longer trials were needed to check it would work well enough as a birth control. And this is not the only prototype hormone-based male contraceptive Prof Wang has been testing. She and colleagues have come up with a body gel men in the UK will be trying as part of an international trial. Users apply it daily to their back and shoulders, where it can be absorbed through the skin.
Progestin hormone in the gel blocks natural testosterone production in the testicles, reducing sperm production to low or nonexistent levels, while replacement testosterone in the gel maintains sex drive and other functions that rely on the hormone.
And trials in men have suggested this is safe enough to move into the next phase of testing. Other scientists have been trying delivering longer-acting birth control hormones in a jab given every other month. But they stopped enrolling men to their phase-two study , looking at the safety and effectiveness of the injection, after some of the volunteers reported side-effects, including mood disorders or depression.
For men who don't fancy taking hormones, researchers have been looking at ways to block sperm flow, stopping it from ever leaving the penis - effectively, a non-surgical vasectomy. Vasalgel - a polymer material that is injected into the two ducts that transports sperm from the left and right testicles to the penis - is being developed as a non-hormonal, reversible, long-acting male contraceptive.
So far, it has been tested in animals only - but the researchers behind it have recently received funding to look to begin human trials.
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