If you get really aroused, you have an orgasm or ‘come’. You then ejaculate - semen comes out of your penis.

First ejaculation
Some time between the ages of about 11 and 16, you may have your first ejaculation. This means a sticky white fluid called semen comes out of your penis.

Your first ejaculation can happen when you’re asleep – people often call this a ‘wet dream’. It could also happen when you masturbate or when you make love with someone.

No two boys are the same. This means some boys have their first ejaculation when they’re 11, while others have it when they’re 16.

Wet dreams
A wet dream is when you ejaculate in your sleep. When you wake up and feel the damp patch on your bed, you might think you’ve peed on your bed. But in fact, you’ve just ejaculated semen during your sleep. Often you can have a wet dream without even dreaming about sex.

Wet dreams are also called 'night fall' or 'nocturnal emissions'. They're perfectly natural and do no harm at all - they just leave you a bit wet and sticky!

Read articles about masturbation myths.

How much do you ejaculate?
As you go through puberty, the amount of semen you ejaculate tends to increase and change in texture and quantity.

 
First ejaculation:

• Average amount of semen: 0.5 millilitres
• Colour and texture: clear, jelly-like
• Average amount of sperm: Few sperm – less than a million per millilitre

 
Six months after your first ejaculation:

• Average amount of semen: 1 millilitre
• Colour and texture: clear, jelly-like
• Average amount of sperm: 20 million sperm per millilitre

 
One year after your first ejaculation:

• Average amount of semen: 2.5 millilitres
• Colour and texture: clear or white jelly-like or sticky liquid
• Average amount of sperm: 50 million sperm per millilitre

 
Two years after your first ejaculation – the same as an adult:

• Average amount of semen: 3.5 millilitres
• Colour and Texture: white sticky liquid
• Average amount of sperm: 300 million sperm per millilitre

For the sake of comparison, a teaspoonful is 5 millilitres.

First ejaculations and pregnancy
In 90 percent of boys, when they ejaculate for the first time, the semen doesn't actually contain any sperm – the cells that fertilise an egg to get a girl pregnant. But... there's no way to guarantee whether your first ejaculation will contain any sperm or not. So always use contraception when you have sex with a girl. The safest is to go 'double Dutch' – wear a condom and use another form of contraception!

 
Did you know...?
A teaspoonful of semen can hold 100 million sperm.