Skip to content

Randomised trial, 2026

Does taking alpha-lactalbumin supplement for three months help with period-related symptoms?

No significant overall difference compared to placebo. Some exploratory analyses found minor improvements in weight gain and lowered motor coordination, and possibly in quality of life. These exploratory findings need confirmation.

Strong study design 140 healthy women aged 20-39 years in Japan

What they did

A double-blind randomized trial with 140 healthy Japanese women aged 20-39 years. They took either 900 mg of alpha-lactalbumin or placebo daily for three menstrual cycles. Symptoms were measured each cycle.

What they found

The main outcome, the Menstrual Distress Questionnaire, showed no significant overall differences between groups. In exploratory analyses, alpha-lactalbumin did reduce two specific symptoms: weight gain and lowered motor coordination. Secondary measures suggested potential benefits in work and social quality of life.

What it means for you

The supplement did not improve most period symptoms overall in a rigorous trial. The minor benefits found in exploratory analyses were not the main findings and need confirmation in new studies, which limits confidence.

140

women in the study

900 mg/day

alpha-lactalbumin dose

3

menstrual cycles

About the study

Original title
Effect of long-term intake of <i>α</i>-lactalbumin on menstruation-related symptoms and quality of life in healthy Japanese women: a randomized, double-blind, placebo-controlled study
Authors
Ito K, Yamazaki K, Natori A
Journal
Frontiers in nutrition
Year
2026
Study design
Randomised trial
Participants
140
What was tested
Alpha-lactalbumin 900 mg daily or placebo for three menstrual cycles
Open access
Yes
Original abstract

Background/objectives: Coping strategies for menstruation-related symptoms are required to support women's health-related quality of life (QoL) and the continued social advancement of women. Previous studies have reported that short-term intake of α -lactalbumin (aLA) alleviates physical symptoms during menstruation. In this study, we investigated the effects of long-term intake of aLA on menstruation-related symptoms and QoL in healthy Japanese women. Methods: A randomized, double-blind, placebo-controlled study was conducted. Participants were 140 healthy women aged 20-39 years and were randomly assigned to receive aLA (900 mg/day) or placebo for three menstrual cycles. Premenstrual and intramenstrual symptoms were assessed at each cycle. The primary outcome was subjective symptoms on the Menstrual Distress Questionnaire (MDQ), and secondary outcomes were the 36-Item Short Form Health Survey (SF-36), subjective symptoms on the Visual Analog Scale, and urinary prostaglandins. Results: The primary outcome, the MDQ, showed no significant differences in the total score or the six factor scores between groups, either premenstrually or during menstruation. In exploratory analyses, aLA intake significantly alleviated the premenstrual MDQ sub-scores "Weight gain" and "Lowered motor coordination" compared with placebo ( p p < 0.05). No significant group differences were observed for other items. Conclusion: In this trial, long-term aLA supplementation did not improve overall menstruation-related symptoms as assessed by the primary outcome. However, secondary outcomes indicated potential benefits in role-related and social aspects of premenstrual QoL. These findings are exploratory, requiring further studies for confirmation. Clinical trial registration: https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000063507, UMIN-CTR UMIN000055576.

Reproduced under CC-BY.

Topics