What is the difference?

Contraceptive implant vs Contraceptive injection

The implant and the injection both use a progestogen hormone, involve no daily pill and are often discussed as alternatives. The biggest differences are how long each one lasts, how reliable it is in everyday use and how quickly fertility returns after stopping.

General information, not medical advice. For advice about your own situation, talk to a clinician, pharmacist or sexual health clinic.

Contraception

Contraceptive implant

The contraceptive implant is a small flexible rod placed under the skin of the upper arm that releases a progestogen and prevents pregnancy for up to five years.

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Contraception

Contraceptive injection

The contraceptive injection is a progestogen injection given every 8 to 13 weeks, depending on the type, that mainly prevents pregnancy by stopping ovulation.

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Side by side

Contraceptive implantContraceptive injection
What it isContraceptive implantA small flexible rod placed under the skin of the upper arm.Contraceptive injectionAn injection of progestogen, given by a clinician or, for one type, self-injected.
How long it lastsContraceptive implantSeveral years: the NHS and Planned Parenthood now say up to 5 years.Contraceptive injection8 to 13 weeks, depending on the type, then it must be repeated.
Typical-use effectivenessContraceptive implantMore than 99%, because there is nothing to remember.Contraceptive injectionAbout 94%, mostly because repeat injections are sometimes late.
Return of fertilityContraceptive implantQuickly, as soon as it is removed.Contraceptive injectionCan take up to a year after the last injection.
Stopping earlyContraceptive implantCan be removed at any time by a trained clinician.Contraceptive injectionCannot be removed; its effect wears off over the following weeks.
Other pointsContraceptive implantChanged bleeding patterns are the most common side effect.Contraceptive injectionLong-term use is linked to a small, mostly reversible fall in bone density.

In short

The implant is a fit-and-forget method that is easy to reverse; the injection is a repeat appointment every few months and is slower to wear off. A clinician can help weigh them up.

What they have in common

Both are progestogen-only, so they suit many people who cannot take estrogen; both often change periods, sometimes stopping them; and neither protects against STIs.

Sources

  1. NHSContraceptive implant
  2. NHSContraceptive injection
  3. Planned ParenthoodBirth control shot

More comparisons

Last reviewed 16 October 2026. Spotted a mistake?