Most research on red light therapy focuses on muscle recovery, skin, and pain. That makes sense, because that is where the largest body of research lies. But there is an entire category of complaints that is rarely addressed: everything related to the female cycle, hormones, and the pelvic area. Menstrual pain. Endometriosis. Recovery after childbirth. Nipple pain during breastfeeding. Menopause.

A comprehensive interview on precisely this topic was recently published with midwife Tracy Donegan on Light Therapy Insiders. In this article, we summarize her insights, supplement them with what scientific research does and does not say about it, and translate them into what you can do with it at home.

This article follows the stages of life. Are you specifically looking for information about hormonal imbalance, PCOS, PMS, or the impact of stress on your cycle? Then read our article on red light therapy and female hormones.

Contents

• How does red light therapy work in your body?
• Red light therapy for menstrual pain
• Red light therapy for endometriosis and pelvic pain
• Red light therapy and fertility
• Pregnancy: where it is better not to use red light
• Red light therapy after childbirth
• Red light therapy during menopause
• How do you start with red light therapy?
• Is red light therapy safe?
• Frequently asked questions

How does red light therapy work in your body?

Red light (around 660 nm) and near-infrared light (around 850 nm) penetrate the skin and are absorbed by your mitochondria, the energy factories in your cells. An enzyme called cytochrome c oxidase captures the light there. The result: your cells produce more ATP, blood flow in the treated area improves, and inflammatory signals are adjusted.

That may sound abstract, but it explains why such diverse complaints respond to the same therapy. Red light does not treat a specific condition. It gives tissue more energy to repair itself. Tissue that is under strain, recovering from childbirth, or receiving less blood flow due to falling estrogen levels benefits the most.

The technical term for this is photobiomodulation. If you want to explore this in more depth, read our article on how red light therapy works exactly or on mitochondria and ATP.

Red light therapy for menstrual pain

Of all applications specific to women, menstrual pain has been studied the most. And the results are striking.

In a randomized multicenter study published in Lasers in Medical Science, 156 women with primary dysmenorrhea (menstrual cramps without an underlying condition) were divided into two groups. One group received LED light therapy at two points low on the abdomen for three cycles. The other group received the contraceptive pill (ethinylestradiol/desogestrel).

The percentage of women who achieved a clinically relevant reduction in pain was comparable in both groups: 73.6% with light therapy versus 85.7% with the pill. That difference was not statistically significant. The absolute reduction in pain was greater with the pill. Interestingly, blood levels of prostaglandin E2 (the substance that causes the cramps) fell equally in both groups.

That is a noteworthy finding. Not because light is "better" than the pill—the pill clearly wins in terms of absolute pain reduction. But because it puts a serious option on the table for women who do not want to or cannot use hormones. To be fair, though: this study did not include a sham-treatment group, so some of the improvement may be due to a placebo effect.

More important is the study in which light therapy was compared with a sham treatment. A 2025 meta-analysis found three such studies, involving 150 women in total, and found a clear reduction in pain in favor of light therapy. In the best-designed individual study (double-blind, with a placebo device, 88 women), the pain score fell by 4.3 points, compared with 1.8 in the placebo group. These studies are still small and all come from East Asia, so replication in Europe is still needed. But of all the applications discussed in this article, this one has the strongest evidence.

In practice, you use a flexible light therapy belt worn low around your abdomen or lower back, or sit in front of a panel. Twenty minutes, preferably not only once the pain has already started: begin a few days before your period.

Red light therapy for endometriosis and pelvic pain

Endometriosis is more complicated. There is no good research showing that red light targets endometriosis tissue, and we should not suggest that it does.

What does seem plausible is the pain-relieving effect. Near-infrared light reaches deeper tissue, improves local blood flow, and reduces inflammatory activity. For women who live with pelvic pain every day, a non-drug adjunct that you can use at home without putting strain on your stomach or becoming dependent is worth trying.

Important: red light therapy does not replace treatment for endometriosis. Think of it as something you add, in consultation with your doctor. Read more about its effect on pain in our article about red light therapy for pain and inflammation.

Red light therapy and fertility

In the interview, Donegan makes a point that is still too often overlooked in the consultation room: when a couple’s desire to have children is not fulfilled naturally, the cause lies, at least in part, with the man in a substantial proportion of cases. Yet the process often focuses exclusively on the woman.

For men, research suggests that photobiomodulation may support sperm motility. After all, mitochondria provide the energy that enables a sperm cell to swim. A practical point here: sperm production takes approximately 70 to 76 days. What you do today will not show up in a semen analysis until more than two months from now.

That also explains why Donegan asks her clients who are trying to conceive to follow a protocol for at least three months before drawing conclusions. That is clinical experience, not a study result, but it aligns neatly with the biology.

For women, the evidence is less conclusive. Red light on the lower abdomen is used to support blood flow to the pelvic area, but there is no robust outcome data on pregnancy rates. Be honest with yourself here: this is a reasonable adjunct, not a fertility treatment. We wrote a separate article about the hormonal side of this: red light therapy and female hormones.

Pregnancy: where it is better not to use red light

Clear and straightforward: do not use a powerful red light panel directly on your pregnant abdomen unless it is done under the supervision of a healthcare professional trained in this area.

There is no evidence that it is harmful, but there is also no research demonstrating that it is safe. During pregnancy, that difference is important enough to warrant caution.

Light applied to your shoulders, neck, face, or lower back is a different matter, because it remains far from the uterus. Unsure? Discuss it with your midwife. We have written a full article about this: red light therapy during pregnancy.

Red light therapy after childbirth

This is the area with the most clinical research, and the results are mixed but promising.

Nipple pain and nipple cracks during breastfeeding

This is more nuanced than what you often read online. There are positive meta-analyses, but they usually compare light therapy with standard care such as lanolin or breast milk. Compared with a sham treatment—the more rigorous test—the effect has not yet been demonstrated: a 2024 review found exactly two such studies, involving a total of 139 women, and found no significant difference. It is also established that a single session does not work.

Still, that is not the end of the story. The latest double-blind, sham-controlled study, from 2026, used a repeated protocol with both red and infrared light and found less pain for up to seven days after treatment. The evidence is moving in the right direction. It has not yet been proven, and that is not how we present it.

One caveat you read everywhere—and that is correct—is that light cannot fix an incorrect latching technique. If the cause lies in the latch, the wound will keep reopening. See a lactation consultant first, and use the light alongside that support.

Perineal and cesarean recovery

For perineal injuries, stitches, and recovery after a cesarean section, the picture is more mixed. Some RCTs show clear pain reduction, while systematic reviews conclude that the difference from placebo is small or not significant. The doses and wavelengths used vary considerably between studies, which partly explains the difference. In short: it may be useful, but the evidence is not yet conclusive.

Practically speaking: wait until the bleeding is under control and the wound has closed, and consult your midwife or doctor before you begin.

Red light therapy during menopause

When estrogen levels drop, all kinds of things change at once. Your skin becomes thinner and drier, collagen production decreases, tissue in the pelvic area becomes more vulnerable, your sleep becomes more restless, and you recover more slowly from exertion.

The common theme is striking: it concerns tissue receiving less blood and cells functioning less efficiently. And that is precisely what photobiomodulation targets.

Skin and collagen

The evidence is strongest for the skin, compared with everything else related to menopause. In a double-blind study in which one side of the face received light and the other a sham treatment, wrinkles and skin roughness measurably decreased. More importantly, skin biopsies actually showed more collagen and elastic fibers. This is one of the few instances in which the effect has been demonstrated directly in human tissue, rather than only through a questionnaire.

An honest caveat is needed here. A considerable share of research into LED light therapy is paid for by device manufacturers, and the most recent independently funded study did not meet its primary endpoint. The effect is real but modest. Expect visibly smoother skin texture, not the result of a procedure. Read more about this in our article on red light therapy for the skin. An LED facial mask is the simplest option for this.

Genital and pelvic symptoms

For dryness, thinning tissue, and pain during sex, interest is high and the evidence is still emerging. Randomized research into photobiomodulation for genitourinary syndrome of menopause is now underway, but the results are not yet available. If you read that it is "proven to work" for this purpose, that is not correct at this time.

Sleep and energy

Here, something else applies, and it is not about irradiating tissue but about your biorhythm. Bright, blue-rich light in the evening keeps you awake; warm, red light does not. An evening session therefore fits perfectly into a wind-down routine. Read more about this in our article on red light therapy for better sleep.

How do you start with red light therapy?

The great thing about light therapy is that the protocol is simple. The difficult part is that consistency turns out to matter more than intensity, and that is where things usually go wrong.

• Start slowly. Ten to fifteen minutes per area is enough to begin with. More is not better; photobiomodulation has an optimal dosing range, and beyond that, the effect actually decreases again.
• Keep your distance. For a panel, 15 to 30 cm is typical. A belt or mask rests directly on the skin.
• Be consistent. Using it three to five times a week delivers more than one long session on the weekend.
• Give it time. Skin and pain complaints often respond within two to four weeks. For anything related to the cycle or hormones, expect two to three cycles.
• Not noticing anything at all after about four weeks? Then it makes sense to review your protocol: distance, duration, or frequency, rather than simply continuing.

Is red light therapy safe?

Red light therapy has a favorable safety profile. It contains no UV, does not burn your skin, and the side effects reported in studies are rare and mild. Still, there are a few clear points to keep in mind:

• Do not treat moles or skin spots that look suspicious. Have them assessed first.
• Do not use a powerful panel directly on a pregnant abdomen without supervision.
• Do not aim intense panels at newborns.
• Are you taking photosensitizing medication (certain antibiotics, some treatments for acne or autoimmune diseases)? Consult your doctor or pharmacist first.
• Do not look directly into the LEDs. With large panels at close range, protective eyewear is advisable.

Frequently asked questions

Does red light therapy help with menstrual pain?

Probably. Three placebo-controlled studies involving a total of 150 women showed a clear reduction in pain, and in a comparison with the contraceptive pill, 73.6% of women using light achieved a clinically relevant improvement compared with 85.7% using the pill. The studies are small, so there is not yet certainty.

Can you use red light therapy during pregnancy?

Not directly on your abdomen, unless supervised by a trained healthcare professional. There is no evidence of harm, but there is also no research demonstrating its safety. On your shoulders, neck, face, or lower back, it is a different story because these areas are far from the uterus.

Does red light therapy help with menopausal symptoms?

The evidence for skin is reasonably solid: thinning skin and collagen loss demonstrably respond to red light. Research into genital and pelvic complaints such as dryness and pain during sex is still ongoing, so there is nothing to promise yet.

How long does it take before you notice results?

Skin and pain symptoms often respond within two to four weeks with three to five sessions per week. For anything related to your cycle or hormones, expect two to three cycles. If you notice no improvement at all after four weeks, first take a critical look at the distance, duration, and frequency.

Is red light therapy safe while breastfeeding?

Yes. Light therapy applied to the nipple is specifically used in clinical research for cracked nipples and has no effect on milk production. However, light cannot correct an improper latch. Consult a lactation consultant first and use the light alongside that.

Which device do you need for lower-abdominal symptoms?

A flexible light therapy belt worn low around your abdomen or lower back is the most practical option for this, because you can keep it on while resting. A standing panel works too, but requires you to sit still in front of the device for twenty minutes.

What you can realistically expect

Women’s health has been underrepresented in medical research for decades, and that shows in this topic: the evidence is reasonably solid for menstrual pain and skin concerns, while research on pelvic symptoms during menopause is still in its early stages.

That doesn’t make red light therapy a miracle cure. But it does make it a safe, non-hormonal option you can use at home alongside what you’re already doing. And for some complaints where conventional options are limited, that’s more than nothing.

Questions about which device is right for what you want to address? Feel free to ask. We’re happy to help you decide.

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Disclaimer: this article is for informational purposes only and is not medical advice. Red light therapy does not replace treatment by a doctor. Do you have symptoms, are you pregnant, breastfeeding, or taking medication? Consult your general practitioner, midwife, or specialist before you begin.

Inspired by the interview with midwife Tracy Donegan, Light Therapy Insiders. Scientific support includes: Complementary Therapies in Medicine (2025) and Lasers in Medical Science (2022) on light therapy for primary dysmenorrhea; Breastfeeding Medicine (2024) and Lasers in Medical Science (2025) on photobiomodulation for nipple injuries; Lee et al. (2007) on LED phototherapy with skin biopsies; and an umbrella review in Systematic Reviews (2025) on the overall strength of evidence for photobiomodulation.