Spotting on HRT: What’s normal and when to check in

Starting hormone replacement therapy (HRT) can feel like a huge step toward getting relief from perimenopause or menopause symptoms. But as with any new treatment, your body may need time to adjust. One of the most common things women notice in the early months is spotting or unexpected bleeding. It can be unsettling - especially if you thought your bleeding days were behind you - but in many cases, spotting is a normal, temporary part of the adjustment process. Still, there are times when it signals something else that needs attention. Here’s what you need to know.

Table of contents

1. Why spotting happens when starting HRT

2. How long spotting usually lasts

3. The role of the Mirena coil and HRT

4. When spotting means your hormones need adjusting

5. When spotting should be investigated further

6. Practical steps and reassurance

Why spotting happens when starting HRT

When you begin HRT, your body is introduced to oestrogen and progesterone in new ways - either through tablets, patches, gels, or a combination. These hormones regulate the growth and shedding of the womb lining, so any change in balance can temporarily affect bleeding patterns. Spotting is particularly common in the first months of treatment. Think of it as your womb lining adapting to a new hormonal rhythm. The tissue is sensitive to fluctuations, and until hormone levels stabilise, light bleeding or spotting can occur.

How long spotting usually lasts

For many women, spotting settles within the first six months of starting HRT or after making changes to the regimen. During this adjustment phase, irregular bleeding is considered normal and not usually a cause for concern. That said, if spotting continues beyond this timeframe, it’s worth discussing with your doctor. Sometimes a small tweak in the type or dose of hormones is all that’s needed to restore balance.

The role of the Mirena coil and HRT

The Mirena coil (a hormonal intrauterine system, or IUS) is often used alongside HRT to provide the progesterone component needed to protect the womb lining. One of its known side effects, however, is spotting - especially in the first months after insertion. The good news? This is usually short-lived. If spotting persists, adding a small amount of oestrogen temporarily can often resolve the problem. Over time, many women with a Mirena notice their bleeding becomes lighter or stops altogether, which can be a welcome relief.

Tip: If you have a Mirena and spotting continues, don’t assume it’s failing - sometimes it just needs a little hormonal fine-tuning.

When spotting means your hormones need adjusting

Spotting on HRT isn’t always just about the body adjusting; sometimes it signals that the balance between oestrogen and progesterone isn’t quite right.

• Too much oestrogen: If oestrogen stimulates the womb lining without enough progesterone to keep it in check, spotting or irregular bleeding can result.

• Too little progesterone: In sequential HRT (where progesterone is taken for part of the month), insufficient progesterone may lead to breakthrough bleeding. Adjusting the dose or changing how progesterone is given (oral vs vaginal) can often make a difference.

This is why ongoing dialogue with your healthcare provider is so important. A few small adjustments can usually bring things back into balance.

When spotting should be investigated further

While spotting is common during the first six months of HRT or after a change in treatment, there are times when it deserves closer attention. You should contact your doctor if:

• spotting continues after six months

• bleeding is heavy, painful, or unpredictable

• you notice bleeding after a long time without periods (postmenopausal bleeding)

• you have other concerning symptoms, like pelvic pain or bloating

In these cases, your doctor may suggest investigations such as an ultrasound, a biopsy of the womb lining, or blood tests. These are usually precautionary but can help rule out conditions like fibroids, polyps, or, in rare cases, endometrial cancer.

Practical steps and reassurance

If you’re experiencing spotting on HRT, here are a few things to keep in mind:

• Keep a diary of your bleeding patterns. This helps your doctor see what’s typical for you and whether things are improving.

• Don’t stop HRT suddenly unless advised. Stopping abruptly can worsen symptoms and may not solve the spotting.

• Remember that for many women, spotting is a temporary inconvenience - not a sign of something serious.

Most importantly, don’t suffer in silence. If you’re worried, reach out to your healthcare provider. They’re used to managing these situations and can help you find the right solution.

Key takeaways

• Spotting in the first six months of starting HRT or after changing regimen is common.

• The Mirena coil often causes short-term spotting, which can improve with a small oestrogen boost.

• Ongoing spotting may be a sign of too little progesterone or an imbalance between hormones.

• Persistent or heavy bleeding should always be checked to rule out other conditions.

• Most cases of spotting can be managed with simple adjustments, reassurance, and monitoring.

Refrences:

Thomas, A. M., Hickey, M., & Fraser, I. S. (2000). Disturbances of endometrial bleeding with hormone replacement therapy. Human reproduction (Oxford, England), 15 Suppl 3, 7–17. https://doi.org/10.1093/humrep/15.suppl_3.7

Vilodre, L. C., Osório Wender, M. C., Sisson de Castro, J. A., dos Reis, F. M., Ruschel, S., Magalhães, J. A., & Spritzer, P. M. (2003). Endometrial response to a cyclic regimen of percutaneous 17beta-estradiol and low-dose vaginal micronized progesterone in women with mild-to-moderate hypertension. Gynecological endocrinology : the official journal of the International Society of Gynecological Endocrinology, 17(4), 323–328.

Mattsson, L. Å., Ipsen, H. E., Granqvist, C. J., Kokot-Kierepa, M., & Study Group (2015). Ultra-low-dose estradiol and norethisterone acetate: bleeding patterns and other outcomes over 52 weeks of therapy. Climacteric : the journal of the International Menopause Society, 18(3), 419–425. https://doi.org/10.3109/13697137.2014.999661