At a glance
- GABA (gamma-aminobutyric acid) is the brain's main calming neurotransmitter, involved in mood, anxiety and sleep.
- Progesterone breaks down into allopregnanolone, a steroid that acts directly on GABA receptors.
- In PMDD, the brain seems to react differently to allopregnanolone rather than to abnormal hormone levels.
- A small brain imaging study has found lower GABA levels in mood-related brain regions during the luteal phase in women with PMDD.
- An experimental drug that blocks allopregnanolone's effect on GABA receptors eased PMDD symptoms in a randomized trial.
What is GABA, and how is it linked to PMDD?
GABA and PMDD are linked through allopregnanolone, a progesterone metabolite that acts on GABA receptors differently in people with PMDD than in people without it. GABA itself is the brain's main calming neurotransmitter that slows down nerve activity. It plays a role in:
- sleep
- anxiety
- mood ( [4])
Progesterone breaks down into a steroid called allopregnanolone, which acts directly on GABA receptors. In most people it has a calming, anti-anxiety effect, similar to a mild sedative ( [7]).
In PMDD, research points to a different reaction to allopregnanolone, not abnormal levels of it. Women with PMDD show altered sensitivity to allopregnanolone compared with women without the condition, even when their hormone levels match ( [2], [7]). For how estrogen and progesterone shift across the month, see menstrual cycle hormones, phase by phase. For the full picture on diagnosis, see PMDD (premenstrual dysphoric disorder), explained.
What does the research say about GABA and PMDD?
Brain imaging offers one of the clearest clues. A small study using magnetic resonance spectroscopy found lower GABA levels in two mood-related brain regions (the anterior cingulate cortex and basal ganglia) in women with PMDD during the late luteal phase, compared with women who didn't have PMDD ( [8]).
Other research looks at how the GABA system behaves, not just its resting level:
- Allopregnanolone normally calms the brain, but at luteal-phase concentrations it can have a paradoxical, anxiety-raising effect in sensitive women ( [7]).
- Brain scans show increased amygdala activity, the region that processes fear and anger, during the luteal phase in women with PMDD ( [2]).
- Reviews describe PMDD as likely involving several overlapping biological pathways, with altered GABA and serotonin signaling as a consistent thread ( [4], [5]).
These findings describe a different brain response to a normal monthly hormone shift, not an abnormal hormone level. You can read more on the PMS and PMDD research, summarised page.
Why does this matter for treatment or coping?
Understanding the GABA connection has shaped how PMDD is treated and studied.
- SSRIs, a first-line PMDD treatment, seem to work partly by changing neuroactive steroid levels, not only serotonin. One trial found sertraline changed GABA-related steroid levels in women with PMDD ( [3]).
- Researchers have tested drugs designed to block allopregnanolone's effect on GABA receptors directly. In a randomized trial, a compound called Sepranolone reduced mood symptoms in women with PMDD compared with placebo ( [1], [6]).
- Reviews of GABA-active treatments describe this as a developing field, with more selective drugs still in progress ( [4]).
None of this makes the coping tools on this site a treatment. They can help in the moment. If you want somewhere to put a hard moment before you react, Niyora is a PMS and PMDD support app, and its Moon feature lets you write what happened, see it from another angle, and draft a reply you can hold onto for 20 minutes.
What related terms should you know?
GABA shows up alongside other terms in PMDD research. Here's where to look next.
| Term | What it means |
|---|---|
| Allopregnanolone | The progesterone metabolite that acts on GABA receptors; see Allopregnanolone: what it means |
| Luteal phase | The second half of the cycle, when allopregnanolone and GABA activity shift most; see The luteal phase |
| PMDD causes | A broader look at what researchers think drives PMDD; see What causes PMDD? |
Each term describes a piece of the same mechanism: hormones shift, a metabolite acts on GABA receptors, and some brains react more strongly than others.
From the research library
Research on neurosteroids
167 studies in the library look at neurosteroids in PMS and PMDD. They were published from 1994 to 2026, and each one has a short summary of what was tested and found.
167
studies, 1994 to 2026
How strong the studies are
- Strong study design
- 11
- Moderate study design
- 45
- Early or limited evidence
- 111
Review, 2026
How well do SSRIs treat PMS?
SSRIs like sertraline and fluoxetine are first-line treatments for severe PMS. They work at low doses, are safe with few side effects, and reduce symptoms by affecting serotonin and brain chemistry related to mood.
Strong study design
Systematic review, 2026
Why do some women experience mood changes linked to their menstrual cycle?
Evidence shows these women have normal hormone levels but heightened sensitivity in their brains and cells to hormone changes. This explains PMDD and some postpartum and perimenopausal mood problems, and has led to new treatments.
Strong study design
Case-control study, 2024
Do steroid hormone levels change differently across the menstrual cycle in women with PMDD?
Yes. Progesterone rises earlier in the cycle in women with PMDD, leading to higher levels around ovulation and a sharper drop in the late luteal phase. This different pattern may trigger symptoms.
Strong study design
Systematic review, 2022
Does the stress hormone cortisol change across the menstrual cycle?
Yes, but only slightly. Across many studies, cortisol was a little higher in the first half of the cycle (follicular phase) than the second half (luteal phase), and higher during a period than right before it, but most other phase comparisons showed no clear difference.
Strong study design
Systematic review, 2022
Is taking antidepressants only at certain times as effective as taking them every day for PMS?
Yes. Intermittent dosing works just as well as taking them every day, with effects starting within hours and peaking within 2 days.
Strong study design
Survey study, 2022
What causes PMS and PMDD and what new treatments are being studied?
PMS and PMDD involve changes in hormone sensitivity, serotonin levels, genetic factors, and inflammation. New treatments under research target progesterone receptors and inflammatory pathways.
Strong study design
Clinical trials
Allopregnanolone and Dynamic GABA-A Receptor Plasticity in Selective Serotonin Reuptake Inhibitor Responsive Premenstrual Dysphoric Disorder
Recruiting now, United States
A Study of Efficacy and Safety of Sepranolone (UC1010) in Patients With Premenstrual Dysphoric Disorder (PMDD)
Completed, Germany
Stress & Premenstrual Symptoms Study
Completed, United States
Questions people ask
What does GABA have to do with PMDD?+
GABA is the brain's main calming neurotransmitter, and PMDD research centers on allopregnanolone, a progesterone metabolite that acts on GABA receptors. People with PMDD seem to react differently to allopregnanolone than people without it, even at matching hormone levels, which may help explain mood symptoms before a period ( [2], [7]).
Is low GABA the cause of PMDD?+
Low GABA isn't the whole story. One brain imaging study found lower GABA levels in two mood-related regions in women with PMDD during the late luteal phase ( [8]), but researchers think PMDD likely involves several overlapping pathways, not one single cause ( [5]).
Can you raise GABA to help with PMDD?+
There's no proven way to simply raise GABA to treat PMDD. Treatments that act on the GABA system, like SSRIs and experimental allopregnanolone-blocking drugs, have helped in trials ( [1], [3]), but a doctor needs to assess what fits your symptoms and history.
Is GABA the same thing as allopregnanolone?+
No. GABA is a neurotransmitter, and allopregnanolone is a steroid made from progesterone that acts on GABA receptors. Allopregnanolone can calm the brain at some levels and, in sensitive people, unsettle mood at others, which researchers study closely in PMDD ( [6], [7]).
Sources
- 1.Treatment of premenstrual dysphoric disorder with the GABA A receptor modulating steroid antagonist Sepranolone (UC1010)-A randomized controlled trial, Psychoneuroendocrinology, 2017
- 2.Effects of GABA active steroids in the female brain with a focus on the premenstrual dysphoric disorder, Journal of neuroendocrinology, 2018
- 3.GABAergic neuroactive steroid response to sertraline in premenstrual dysphoric disorder, Psychoneuroendocrinology, 2024
- 4.Modulators of GABA A receptor-mediated inhibition in the treatment of neuropsychiatric disorders: past, present, and future, Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 2024
- 5.Towards understanding the biology of premenstrual dysphoric disorder: From genes to GABA, Neuroscience and biobehavioral reviews, 2023
- 6.Positive GABA A receptor modulating steroids and their antagonists: Implications for clinical treatments, Journal of neuroendocrinology, 2022
- 7.GABAA Receptor-Modulating Steroids in Relation to Women's Behavioral Health, Current psychiatry reports, 2015
- 8.Alterations of GABA and glutamate-glutamine levels in premenstrual dysphoric disorder: a 3T proton magnetic resonance spectroscopy study, Psychiatry research, 2015