The Recent Addition of Implanon to the Brazilian National Health System (SUS) represents an important advance in access to long-acting contraceptive methods in Brazil. The implant, which can cost thousands of reais in the private sector, is now being made available for free, with plans for large-scale distribution over the coming years.

However, despite expanded access, the decision to use Implanon should be conscious and individualised. Below, you will find a complete guide, based on scientific evidence, explained clearly.

What is Implanon and how does it work

Implanon is a small flexible rod placed under the skin of the arm, which continuously releases a hormone called etonogestrel for up to 3 years.

It prevents pregnancy in two main ways:

  • Prevents ovulation

  • Makes the cervical mucus thicker, making it difficult for sperm to enter

It is considered one of the most effective contraceptive methods available, with an extremely low failure rate.

Who can have it placed via the NHS

The offer via the NHS is being expanded progressively. Initially, some groups had priority (such as women in specific health or vulnerability situations), but the current proposal is to expand access to women of reproductive age.

In practice, the criteria can vary according to how the local health service is organised, including:

  • Prior medical assessment

  • Absence of contraindications

  • Availability of the method in the network

In other words: it is not just a matter of "wanting to have it placed" — there is a care pathway that needs to be followed.

Who can use it (and who should not)

Can use:

  • Women who want a long-acting method

  • Those who have difficulty remembering to take daily contraception

  • Those who cannot use oestrogen (e.g. certain clinical conditions)

Should not use:

  • Pregnancy or suspected pregnancy

  • History of active thrombosis

  • Severe liver disease

  • Hormone-sensitive cancer

  • Uterine bleeding without a definite diagnosis

In addition, some medications may interfere with effectiveness, which requires individual assessment.

Do you need to have tests beforehand?

Not always.

In most cases, clinical diagnosis and medical assessment are sufficient. The main thing is to rule out pregnancy and identify contraindications.

Tests may be requested if there are specific concerns, such as:

  • Significant menstrual irregularity

  • Liver disease

  • Associated clinical situations

What to know before having it placed

Here is a critical point — many patients have Implanon placed without fully understanding the impact on their body.

You mainly need to know about the bleeding pattern.

Bleeding: the most common effect (and most underestimated)

Implanon does not maintain a predictable menstrual cycle.

What can happen:

  • Irregular bleeding

  • Small frequent spotting

  • Complete absence of menstruation

  • Or, in some cases, prolonged bleeding

Important:
This does NOT mean the method is not working.

But:
If bleeding is heavy or persistent, medical assessment is necessary.

Acne, skin and weight: what to expect in practice

Acne

It can happen — it is a relatively common effect.

  • Some women experience worsening

  • Others see no change

It is not possible to predict with precision before use.

Weight

Weight gain is not the rule, but can occur in some users.
It is often related to increased appetite, and not directly to the hormone.

Other possible effects

  • Headache

  • Mood changes

  • Breast tenderness

  • Decreased libido

  • Pain at the implant site

How to prepare for side effects

Here comes an important strategic tip:

The greatest factor in success with Implanon is not the method itself — it is having the right expectations.

Before having it placed, you need to know:

  • Bleeding can change completely

  • The body needs time to adapt (especially in the first few months)

  • Not every adverse effect requires immediate removal

Practical strategies:

  • Follow-up in the first few months

  • Re-evaluation if symptoms persist

  • Individual adjustments, where necessary

Is it worthwhile?

From a medical perspective, Implanon is:
✔ Highly effective
✔ Safe for most women
✔ Practical (does not depend on daily use)

But:
It is not the best method for everyone

The main factor in dissatisfaction is not method failure — it is intolerance to the bleeding pattern.

Implanon represents an important advance in public health by expanding access to a modern and effective contraceptive method.

However, the choice should be individualised, based on medical assessment and, above all, on clear information about benefits and possible effects.

This content is for informational purposes and does not replace a medical consultation. In case of doubts or for personalised assessment, consult a healthcare professional.

Dr Rebeca Soares Andrade CRM-GO 39335