Can Hormone Treatment Calm Adenomyosis Symptoms Over Time? What an 18 Month Follow Up Study Found

Living with adenomyosis can mean planning your life around pain and bleeding—painful periods (dysmenorrhea), heavy menstrual bleeding, and sometimes other ongoing pelvic pain symptoms that don’t neatly follow a calendar. If you also have endometriosis, the picture can feel even more complicated, because symptoms may overlap and imaging findings can change over time.

A 2025 study in the Journal of Personalized Medicine followed premenopausal people with ultrasound evidence of adenomyosis (with and without endometriosis) for 18 months to see what happened to symptoms and ultrasound findings in those who used continuous hormonal treatment compared with those who did not. This kind of real‑world, longer follow‑up matters because many patients are trying to decide whether staying on medication is “worth it” over time—especially when side effects are part of the trade‑off.

This article walks through what the study observed, what it might mean for day‑to‑day decision-making, and what the study cannot prove.

Key Findings

Why this study was done

The researchers aimed “to evaluate the impact of hormonal therapy” on painful symptoms over “an 18‑month follow‑up,” and they also wanted to “explore sonographic changes” (changes seen on ultrasound) alongside symptoms. In other words, they weren’t only asking, “Do people feel better?”—they also asked, “Does the uterus (and any coexisting endometriosis) look different on imaging over time?”

Importantly, this was described as a pilot retrospective observational study. That means the researchers looked back at what happened in a group of patients rather than randomly assigning treatment.

Who was included (and how adenomyosis/endometriosis were assessed)

The study included “40 women with ultrasound evidence of adenomyosis with and without endometriosis.” Symptoms were tracked using a VAS (Visual Analog Scale), described as a “10 cm Visual Analog Scale,” where 0 means no pain and 10 means the maximum pain.

Adenomyosis and endometriosis were assessed by ultrasound during follow‑up. The paper also notes that there is “no consensus currently exists within the MUSA group” for grading severity in a standardized way, which matters when interpreting how “mild” vs “severe” disease is classified across studies.

What treatment was studied

Twenty patients initiated treatment: “Twenty patients initiated continuous progestin therapy with Dienogest 2 mg per day.” The comparison group was not a placebo group; it consisted of people who chose not to use hormonal treatment: “twenty declined hormonal treatment.” That choice is important, because people who accept or decline treatment can differ in ways that affect outcomes (for example, symptom severity, side-effect concerns, or other health factors), even if those differences aren’t fully captured in the data.

Symptom changes over time

One of the most striking reported findings was for dysmenorrhea and heavy menstrual bleeding in the treated group. The authors report that these symptoms “completely disappear in patients on continuous hormone therapy,” with dysmenorrhea changing from “VAS 7 ± 1.8 SD T0 vs. VAS 0 after 6 months,” and this improvement was sustained through 18 months per the study’s summary claim.

In contrast, among people who did not receive hormonal therapy, the paper reports that “symptoms either remain unchanged or may worsen over time.” Because this was not a randomized trial, the study cannot prove treatment caused the differences—but it does describe two clearly different symptom trajectories in the groups they followed.

The paper also notes that not every symptom improved to zero for everyone. It reports that other pain symptoms improved more slowly and did not always fully resolve, with “VAS scores decreasing to 4 after 18 months” for those symptoms (the study does not provide further detail in the extracted summary about which specific symptoms were included in this “other pain” category).

Ultrasound changes: what happened to adenomyosis and endometriosis findings?

The study also tracked what the disease looked like on ultrasound over time.

In the treated group, the authors describe a “progressive reduction in focal adenomyosis among treated patients,” with focal adenomyosis reported as “25%… 15%… 10% at 18 months.” In the untreated group, ultrasound suggested “worsening in disease extent,” including a shift toward more diffuse or mixed patterns.

For participants with endometriosis, there was a specific finding about endometriomas (ovarian cysts related to endometriosis). In treated patients with endometriomas, the maximum diameter decreased significantly by 18 months, from “T0: 38.4 ± 11.1 mm vs. T3: 18.5 ± 8.1 mm.” The study summary also states that “other endometriosis sites were stable in size.” The extracted analysis notes that the number of treated patients with concomitant endometriosis was not fully detailed in the Results and appears to rely on a table reference.

Side effects reported with treatment

Symptom relief is only one side of the equation. This study reported a notable rate of side effects in the hormone-treated group: by 18 months, “nearly half of the patients undergoing hormone therapy experienced hypoestrogenism-related side effects.” The examples listed include “vaginal dryness, decreased libido, and mood disturbances.” The study reports that none of these symptoms were reported in the untreated group (“no patients in the non-treatment group”).

Hypoestrogenism-related side effects are symptoms that can happen when estrogen effects in the body are reduced. The study does not report strategies for preventing or treating these side effects, and it does not report whether side effects led anyone to stop treatment.

What This Means For You

If you are deciding whether to try (or stay on) continuous dienogest for adenomyosis symptoms, this study offers a real-world picture of what may happen over a longer stretch of time—while also showing the trade‑offs.

Here are the most practical takeaways that come directly from what the researchers reported:

• • In this study, people who took continuous dienogest (2 mg/day) had dysmenorrhea and heavy menstrual bleeding drop to zero by 6 months and stay improved through 18 months (“VAS 0 after 6 months”).
  • If you choose not to use hormonal treatment, this study observed that symptoms “either remain unchanged or may worsen over time” during 18 months of follow‑up.
  • Imaging did not stay static: ultrasound findings appeared more stable or improving with treatment and more worsening without treatment, including “worsening in disease extent” in untreated patients. If you’re already getting ultrasounds, you may want to ask your clinician whether regular follow‑up imaging could help track changes over time in your specific case.
  • Side effects are not rare. By 18 months, “nearly half” of treated patients reported hypoestrogenism-related issues such as “vaginal dryness, decreased libido, and mood disturbances.” If you start treatment, consider planning ahead with your clinician for side‑effect monitoring and what you’ll do if they become disruptive.

This study does not report fertility outcomes, pregnancy outcomes, or whether treatment changed the need for surgery—so if those are your main concerns, you’ll need other evidence and individualized counseling.

Important Limitations

This study provides useful clues, but there are several reasons to treat the findings as suggestive rather than definitive:

• • It cannot prove cause and effect. This was a “pilot retrospective observational study,” meaning people were not randomized to treatment. Improvements could be associated with treatment without being solely caused by it.
  • The sample was small. Only “40 patients” were included, which limits how confidently these results apply to the broader adenomyosis/endometriosis community.
  • Ultrasound grading is not fully standardized. The authors state “no consensus currently exists within the MUSA group” for severity grading, so “improvement” or “worsening” on ultrasound may not translate perfectly across different clinics or studies.
  • Some outcomes are suggested, not demonstrated. The paper discusses future possibilities (including fertility-related questions), but this study itself does not demonstrate fertility preservation or improved reproductive outcomes; the abstract notes “Further larger-scale... studies are needed.”