If you or someone you love is facing breast cancer, it is understandable to wonder whether cannabis or CBD could help. Cannabis and CBD have not been proven to cure breast cancer and should never replace cancer treatment. Where cannabinoids may have a role is in supportive care. Certain cannabinoid medicines have evidence for difficult chemotherapy-related nausea and vomiting, while researchers continue to study cannabis and CBD for pain, sleep, appetite, and quality of life. Because CBD and THC can cause side effects and may interact with medications, anyone undergoing breast cancer treatment should discuss them with their healthcare team before using them.

Cancer is one of those subjects that I approach not only as a physician, but also as someone who has experienced what it can do to a family. I lost my mother to cancer, and that experience changed the way I think about the person behind a diagnosis. When someone is going through cancer, there are medical decisions to make, but there is also everything happening around those decisions, the worry, the uncertainty, the difficult days, and the family members who simply want to know what they can do to help.

That is one reason this conversation about cannabis and CBD matters to me. When someone you love has cancer, it is completely understandable to search for anything that might help them feel better or give them another option. I understand that desire personally. But I also believe hope has to come with honest information, especially when people are vulnerable.

Most importantly, I want to have this conversation the same way I would want someone to have had it with my own family: with compassion, curiosity, and honesty.

Pearls

• Cancer affects more than the person receiving treatment. It can change everyday life for an entire family, which is why supportive care matters.
• We can be hopeful about cannabis research without turning early findings into promises that haven’t been proven.

What Is Breast Cancer?

Our bodies are constantly making new cells. Normally, those cells grow and divide in an organized way. Cancer develops when abnormal cells begin growing out of control.

In breast cancer, that process begins in breast tissue. Some cancers stay where they started for a period of time. Others grow into surrounding tissue and can eventually spread elsewhere in the body.

One of the first things I want people to understand is that breast cancer isn’t just one disease.

You may hear words like DCIS, invasive, ER-positive, PR-positive, HER2-positive, or triple-negative. You may also hear different stages and grades. You don’t have to become an expert in all of those terms overnight. They help the medical team understand what type of breast cancer is present, how it is behaving, and which treatments are most likely to help.

A breast lump is probably the symptom most people know about, but breast cancer doesn’t always begin with something you can feel. Changes in the size or shape of a breast, skin dimpling, nipple changes or discharge, swelling, or enlarged lymph nodes can also be warning signs. And some early breast cancers produce no noticeable symptoms at all.

When something suspicious is found during an examination or mammogram, doctors may use additional imaging such as ultrasound or MRI. A biopsy, where a small sample of tissue is examined, is what determines whether cancer cells are actually present.

Finding out exactly what kind of breast cancer someone has is important because it guides what happens next.

Pearls

• Two people can both have breast cancer and need very different treatments because their cancers may have very different characteristics.
• Breast cancer doesn’t always produce a noticeable lump, which is one reason appropriate screening remains so important.

Who Gets Breast Cancer?

The American Cancer Society estimates that approximately 321,910 women in the United States will be diagnosed with invasive breast cancer in 2026, with another 60,730 cases of ductal carcinoma in situ, or DCIS. About 42,140 women are expected to die from breast cancer this year. Breast cancer accounts for roughly 1 in every 3 new cancers diagnosed in women.

Age is an important part of the picture. The median age at diagnosis is 63, although about 1 in 10 women diagnosed with breast cancer are younger than 45.

There are also differences across racial and socioeconomic groups. Those differences aren’t simply about biology. Access to screening, insurance, income, transportation, quality healthcare, timely diagnosis, and the ability to complete treatment can all influence someone’s experience with cancer.

Breast cancer can also occur in men. It is much less common, but a breast lump, nipple change, or other suspicious change in a man deserves medical attention too.

I think these numbers are important, but I don’t want us to lose sight of what they represent. A statistic may say “321,910 new cases,” but each number represents a person receiving news that can change their life and the lives of the people around them.

That’s why Breast Cancer Awareness Month should be about more than wearing pink. Awareness should encourage us to know our bodies, keep up with appropriate screening, support the people going through treatment, and make good information easier to find.

Pearls

• Breast cancer becomes more common with age, but younger women can develop it too.
• Breast cancer also occurs in men, so a suspicious breast change shouldn’t automatically be ignored because someone is male.

How Is Breast Cancer Treated?

One of the biggest advances in breast cancer care has been understanding that everyone doesn’t need exactly the same treatment.

Treatment depends on the type of cancer, its stage, its biology, a person’s overall health, and many other factors.

Surgery

Some people have surgery that removes the cancer while preserving much of the breast. Others need a mastectomy.

The benefit is obvious: surgery can physically remove cancer from the breast. But recovery can bring discomfort, scarring, changes in movement, changes in body image, and sometimes lymphedema.

Chemotherapy

Chemotherapy uses medicines that travel throughout the body to attack cancer cells.

It can be lifesaving, but it can also be difficult. Depending on the medications being used, people may experience nausea, fatigue, hair loss, appetite changes, nerve symptoms, and other side effects.

Radiation

Radiation directs energy toward a specific area to destroy cancer cells and reduce the chance that the cancer returns there.

It can be an important part of treatment, although fatigue and skin irritation are common concerns.

Hormone Therapy

Some breast cancers use hormones such as estrogen to help them grow. Medicines can interfere with that process.

These treatments can be extremely important, but some people experience hot flashes, joint discomfort, sexual-health changes, or other side effects.

Targeted Therapy and Immunotherapy

Today, doctors can sometimes target very specific characteristics of a cancer. This has changed the outlook for many people with breast cancer.

The important thing to understand is that treating breast cancer and helping someone manage what comes with breast cancer treatment are two different goals.

Pearls

• Breast cancer treatment is increasingly personalized to the individual and the biology of the cancer.
• A treatment can be working against the cancer while still creating side effects that deserve their own care and attention.

Cannabis, CBD & Breast Cancer: Where Do They Fit?

This is where I want to be very clear without taking away anyone’s hope.

If you search CBD and breast cancer online, you will find claims that CBD kills breast cancer cells, cannabis oil shrinks tumors, or THC can cure cancer.

There is a reason some of those headlines exist. Scientists really have studied cannabinoids in cancer cells and animals, and some of those findings are interesting enough to justify continued research.

But there is a major difference between something happening to cancer cells in a laboratory and that same substance successfully treating cancer in a person.

The National Cancer Institute reviews this research and notes that concentrated THC and CBD oils promoted as cancer cures have not been established in clinical trials as cancer treatments.

The American Society of Clinical Oncology’s guideline on cannabis and cancer is also clear: cannabis and cannabinoids should not replace cancer-directed treatment, and they should not be added with the goal of treating the cancer itself outside a clinical trial.

Pearls

• A cannabinoid affecting cancer cells in a laboratory does not prove that taking that cannabinoid will treat breast cancer in a person.
• Saying that CBD isn’t a proven breast cancer treatment doesn’t mean the research is unimportant. It means the research isn’t finished.

Can Cannabis Help With Nausea During Cancer Treatment?

Chemotherapy can cause nausea and vomiting, although modern anti-nausea medications have made a tremendous difference for many patients.

Sometimes, however, those medications aren’t enough.

Certain prescription cannabinoid medicines, dronabinol and nabilone, are FDA-approved for chemotherapy-related nausea and vomiting in patients who have not responded adequately to standard anti-nausea medicines.

The 2024 ASCO guideline similarly recognizes cannabinoids as an option in selected cases of stubborn chemotherapy-induced nausea and vomiting when standard treatment isn’t controlling it.

It doesn’t mean every cannabis product treats chemotherapy nausea. And it doesn’t mean picking up a CBD gummy and taking it before chemotherapy is equivalent to the cannabinoid medicines that have actually been studied.

Pearls

• Cannabinoids have one of their clearest roles in cancer supportive care for chemotherapy-related nausea and vomiting that hasn’t responded adequately to standard treatment.
• Evidence for a prescription cannabinoid cannot automatically be transferred to every CBD oil, gummy, or cannabis product sold commercially.

What About Pain, Sleep and Appetite?

These are probably three of the most common reasons people with cancer become interested in cannabis.

And they’re very understandable reasons.

Pain

Pain during breast cancer can come from many places. There may be discomfort after surgery, nerve symptoms following certain treatments, joint symptoms during hormone therapy, pain from the cancer itself, or an unrelated back or arthritis problem that existed before the diagnosis.

Cannabis and cannabinoids are being studied for cancer pain, but ASCO concluded that the evidence is currently not strong enough to broadly recommend for or against cannabinoids for cancer pain.

That doesn’t mean a patient can never discuss cannabis for pain. It means we shouldn’t present it as something already proven to work for everyone.

Sleep

Sleep can become difficult during cancer for reasons that have nothing to do with the bedroom.

You may be uncomfortable. Your treatment schedule may have changed your routine. Medications may affect sleep. And sometimes you’re simply lying there thinking about everything that’s happening.

Cannabis and CBD are commonly used by people hoping to sleep better, and researchers are interested in this area. But we still need better cancer-specific studies before making strong claims.

If sleep has become part of your wellness conversation, our Dr. Damas Knowledge Center includes additional education about CBD, cannabinoids, sleep, and wellness.

Appetite

Cancer and cancer treatment can change appetite and even the way food tastes.

THC-containing medicines have been studied for appetite, but again, cannabis isn’t automatically the answer to every appetite problem. Sometimes treating nausea, adjusting medications, or working with an oncology dietitian may be more helpful.

Pearls

• “Cancer pain” isn’t one type of pain. Surgery, nerve injury, medications, the cancer itself, and unrelated health problems can all contribute.
• Before adding cannabis for sleep or appetite, it is worth asking whether another treatable problem, such as nausea, medication side effects, pain, or anxiety, is driving the symptom.

Gummies, Tinctures, Softgels or Topicals: Does the Route Matter?

Yes. How you take CBD or THC matters. Tincture, gummy, softgel, topical, and inhaled cannabis products don’t enter the body in exactly the same way, so the experience can be different too.

For someone going through breast cancer treatment, however, choosing a route shouldn’t begin with, “Which product should I buy?” It should begin with, “What am I trying to help, and is this safe with my treatment and medications?”

Tinctures and Oils

Tinctures are one of the most flexible ways to use cannabinoids because you can more easily adjust the amount you take. When an oil is held under the tongue, some cannabinoids may be absorbed through the tissues in the mouth, while the portion that is swallowed continues through the digestive system.

For someone who wants to explore CBD without the intoxicating effects associated with THC, my Pure CBD Tincture is one option to consider as part of a broader wellness routine.

For people whose main concern is their nighttime routine, I also created Lights Out Drops, a full-spectrum nighttime formula combining CBD with CBN and a small amount of Delta-9 THC. Because it contains THC, it isn’t appropriate for everyone and can cause impairment. This is particularly important during cancer treatment, when someone may already be taking medications that cause sleepiness or interact with cannabinoids.

Neither tincture is a breast cancer treatment. If you’re receiving chemotherapy, hormone therapy, targeted therapy, immunotherapy, or other prescription treatment, talk with your oncology team before adding either one to your routine.

Gummies

Some people don’t enjoy the taste or routine of a tincture, and that’s where gummies can be convenient. They provide a premeasured amount and are easy to incorporate into a routine.

The trade-off is that swallowed cannabinoids take longer to move through the digestive system. This is particularly important with THC because taking another gummy too soon can result in consuming more THC than intended.

For adults specifically looking for a THC-free option, my CBD Isolate Gummies provide 50 mg of CBD per gummy. Again, these are intended for general wellness—not to treat breast cancer or its symptoms.

Capsules and Softgels

Softgels are another simple option for people who don’t want a tincture or gummy. They provide a premeasured serving and can fit easily into an established routine.

My Full Spectrum CBD Softgels are one example. Because full-spectrum products can contain THC, it’s important to know what is actually in the product you’re using—especially if you’re sensitive to THC, need to drive, or are taking other medications.

Convenience doesn’t remove the possibility of interactions, so the same rule applies: during cancer treatment, discuss oral cannabinoid products with your healthcare team.

Topicals

Sometimes the goal isn’t a whole-body effect. Someone may be dealing with localized muscle or joint discomfort and simply want something they can incorporate into massage or body care.

That’s where topical products may make more sense.

My CBD Body Oil, CBD Body Rub, and CBD Sports Cream offer different ways to incorporate CBD into a topical wellness routine.

Breast cancer treatment does require an extra precaution here. Don’t put CBD creams, oils, or rubs over surgical incisions, open wounds, irritated skin, or areas being treated with radiation unless your healthcare team tells you it is appropriate.

Smoking and Vaping

Smoking or vaping cannabis delivers cannabinoids through the lungs, so the effects are generally felt much faster than with gummies or other swallowed products.

But faster doesn’t necessarily mean better.

Smoking exposes the lungs to combustion products, while vaping has its own respiratory and product-quality concerns. For someone whose body is already dealing with cancer and cancer treatment, I would want those risks considered carefully rather than choosing inhalation simply because it works quickly.

The National Cancer Institute’s review of cannabis and cannabinoids discusses the respiratory concerns associated with cannabis smoke and its many similarities to tobacco smoke.

The bigger point is that there isn’t one “best” way to take CBD or cannabis during cancer care. The right conversation starts with the person’s symptoms, medications, treatment plan, previous experience with cannabinoids, and what they’re hoping to accomplish.

Pearls

• Tinctures, gummies, softgels, topicals, and inhaled cannabis behave differently in the body, so the route should match the reason someone is considering a cannabinoid.
• During breast cancer treatment, choosing a CBD or THC product should come after checking for medication interactions and treatment-specific concerns, not before.

One Conversation I Don’t Want You to Skip: CBD and Your Medications

If you’re being treated for breast cancer and you’re considering CBD, please don’t keep it a secret from your medical team.

This isn’t about judgment.

It’s about interactions.

CBD can affect enzymes your body uses to process medications. The National Cancer Institute notes that concentrated CBD oils could potentially change the effectiveness or toxicity of some therapies metabolized through these pathways, although we still need more clinical interaction data.

Think about it this way: if your oncology team carefully selected a medication and dose for you, they should know about other substances you’re taking that might change how your body handles that medication.

ASCO actually encourages healthcare professionals to ask people with cancer about cannabis routinely and without judgment.

That’s exactly how I think the conversation should happen.

If you’re taking medications and want to understand this issue better, I also recommend reading my CBD drug interaction guide.

Pearls

• CBD can interact with the way the body processes medications, so your oncology team should know if you’re using it.
• Bringing the actual CBD or cannabis label to an appointment can be more useful than simply telling your doctor, “I take CBD.”

Rolling It All Up

Writing about CBD and breast cancer is different for me because cancer isn’t something I know only from medical books or patients’ charts. I’ve watched someone I loved go through it. I know how badly families want another option, another answer, or simply something that can make a difficult day a little easier.

That’s why I believe we have to hold onto hope and honesty at the same time.

Cannabis and CBD are not proven treatments for breast cancer. They should not replace surgery, chemotherapy, radiation, hormone therapy, targeted therapy, immunotherapy, or another treatment recommended by your oncology team. At the same time, cannabinoids are being studied for supportive care, and certain cannabinoid medicines already have a recognized role in difficult chemotherapy-related nausea and vomiting. Researchers continue to explore what else these compounds may, or may not, offer.

If you are going through breast cancer treatment and you’re curious about CBD or cannabis, talk with your healthcare team before starting it, especially if you’re taking prescription medications. The goal isn’t to shut down the conversation. The goal is to make sure the conversation is informed and safe.

If CBD eventually becomes part of your broader wellness routine, you can explore the CBD products I created for Dr. Damas Wellness. 

And please keep asking questions. You can explore more physician-led cannabis and wellness education in the Dr. Damas Knowledge Center, learn more about me, Dr. Hervé Damas, read about Dr. Damas Wellness, or contact us if there is something you’d like to ask. We’re happy to hear from you.

If someone in your family or circle of friends is navigating breast cancer and asking the same questions about CBD or cannabis, please share this article with them. Sometimes helping someone starts simply by giving them better information.

Pearls

• Cannabis and CBD may have a place in supportive cancer care for some people, but supportive care and treating the cancer itself are not the same thing.
• If someone you love is going through cancer, you don’t always need to have the perfect thing to say. Being present, listening, and helping them find reliable information can matter too.