Last Updated on November 27, 2025 by Bilal Hasdemir

Patients getting a stem cell transplant often notice a strange smell. It’s like garlic or creamed corn. This smell comes from dimethyl sulfoxide (DMSO), a preservative used to freeze the stem cells. Explore how a calorie deficit may impact FDG uptake and recovery after an FDG PET scan used for cancer and metabolic studies.

This smell can worry patients a lot. Knowing why it happens and how long it lasts can make them feel better. It helps them deal with the anxiety of bone marrow transplant procedures.

Key Takeaways

• The smell after a stem cell transplant is caused by DMSO.
• It is often compared to garlic or creamed corn.
• By understanding the cause of the smell, patients can alleviate their concerns.
• The duration of the smell varies among patients.
• It’s a common side effect of the procedure.

Understanding Stem Cell and Bone Marrow Transplants

It’s important to know the difference between stem cell and bone marrow transplants. Both are used to treat diseases like cancer and blood disorders. This knowledge helps patients and their families make informed choices.

What is a stem cell transplant?

A stem cell transplant is a procedure that puts stem cells into a patient’s body. These cells replace damaged or diseased ones. It helps rebuild the bone marrow, which is key for making healthy blood cells.

Difference between stem cell and bone marrow transplants

Stem cell and bone marrow transplants both use stem cells. But, bone marrow transplants get these cells directly from the bone marrow. Stem cell transplants can use cells from other sources, like blood or umbilical cord blood.

Common reasons for undergoing transplantation

People get stem cell or bone marrow transplants for many reasons. It’s used to treat cancers like leukemia or lymphoma. It also helps with blood disorders like sickle cell anemia. Or, it replaces damaged bone marrow from chemotherapy or radiation.

The Transplantation Process Explained

Stem cell transplantation is a complex process. It needs careful preparation. It includes steps like pre-transplant preparation and the actual transplant.

Pre-transplant Preparation and Conditioning

Before a stem cell transplant, patients go through conditioning. This step removes diseased cells and weakens the immune system. It uses chemotherapy and radiation to prepare the body for new stem cells.

Conditioning Regimens: The conditioning regimen varies based on the patient’s health and the transplant type. Some regimens are more intense than others. The choice depends on the patient’s health and the disease being treated.

The Actual Transplant Procedure

The transplant procedure is straightforward. It involves infusing stem cells into the patient’s bloodstream. This is similar to getting a blood transfusion. The stem cells then go to the bone marrow to produce new blood cells.

Duration and Recovery: The transplant itself is not painful. Patients can usually go back to normal activities soon after. But, recovery can take weeks to months. During this time, blood counts are closely monitored.

How Bone Marrow and Stem Cells are Collected

Stem cells can come from bone marrow or peripheral blood. The collection method depends on the source.

Collection Method	Description	Source
Bone Marrow Harvest	Involves extracting marrow from the hipbone under anesthesia.	Bone Marrow
Apheresis	A process that filters stem cells from the blood.	Peripheral Blood

Knowing these steps is key for patients to understand the transplant process. Each step is important for the transplant’s success.

Donor Experience and Recovery

Thinking about bone marrow donation? It’s important to know what to expect. Donating bone marrow or stem cells can save someone’s life.

What Donors Can Expect During the Procedure

Donors might feel some discomfort during the process. But, it’s usually safe. The donation happens in a hospital or clinic with medical experts watching over you.

Bone marrow donation involves taking marrow from the hip bone. This is done under anesthesia to reduce pain.

Is Bone Marrow Donation Painful?

Even though donors are under anesthesia, they might feel some pain later. This pain is usually managed with medicine.

Recovery Time for Bone Marrow Donors

Recovery times vary, but most donors can get back to normal in a few weeks. How fast you recover depends on your health and the donation method.

Recovery Aspect	Typical Recovery Time	Notes
Return to normal activities	2-4 weeks	Most donors can resume their usual activities within a month.
Full physical recovery	1-3 months	Complete recovery may take longer, depending on individual health.
Pain and discomfort	1-2 weeks	Pain is typically managed with medication.

Long-term Effects on Donors

Studies show that long-term effects of bone marrow donation are usually small. But, like any medical procedure, there are risks and side effects to consider.

Talk to your doctor about your situation and any worries you have. They can help you understand the possible long-term effects.

Recipient’s Journey Through Transplantation

Transplantation is more than one procedure. It’s a journey with preparation, the transplant, and a long recovery. Knowing what to expect can help patients prepare for the challenges.

How long does the transplant procedure take?

The transplant procedure itself is short, taking just a few hours to a day. But the whole process, including getting ready and recovering, can take weeks to months. The time depends on the transplant type, the patient’s health, and how well they respond to treatment.

What happens immediately after transplantation

Right after the transplant, patients are watched closely for any problems. This is a key time for recovery. They usually stay in the hospital for days to weeks, based on their health and the transplant type.

The critical first 30 days

The first 30 days are very important. Patients are at high risk of infections and other issues because their immune systems are weak. They need close care to manage these risks and ensure a good recovery. This is when the new blood cells start to form, showing the transplant is working.

During this time, patients get a lot of help from their healthcare team. They get advice on managing side effects, nutrition, and emotional support. Knowing the recovery timeline and being ready for the first 30 days can greatly improve the patient’s outcome and quality of life.

Common Blood Transplant Side Effects

Blood transplant side effects can differ a lot from person to person. It’s important to know what might happen. Patients getting stem cell or bone marrow transplants face many side effects. These can be immediate or last a long time.

Immediate Post-Transplant Complications

Right after a blood transplant, patients might face several issues. These include:

• Infections because their immune system is weak
• Graft-versus-host disease (GVHD), where the donated cells attack the body
• Organ damage or failure
• Bleeding or hemorrhage

These problems can be serious and need careful watching by doctors.

Short-term Side Effects (Days 1-30)

In the first month after a blood transplant, patients often feel:

• Fatigue and weakness
• Nausea and vomiting
• Diarrhea or constipation
• Mucositis, or inflammation of the mucous membranes

Managing these side effects is key for the patient’s comfort and healing.

Medium-term Side Effects (Days 30-100)

After the first month, patients may continue to face challenges. These include:

• GVHD, which can affect different organs
• Infections, if the immune system takes time to recover
• Organ dysfunction

Regular check-ups with the healthcare team are very important during this time.

Long-term Complications (Beyond Day 100)

Some patients may deal with long-term issues. These can be:

• Chronic GVHD
• Increased risk of secondary cancers
• Hormonal imbalances or other endocrine disorders
• Osteoporosis or other bone-related issues

Long-term follow-up care is key to watch and manage these possible problems.

The Phenomenon of Unusual Smells After Transplantation

Many patients report unusual smells after a stem cell transplant. This has caught the attention of doctors. The smell is often linked to Dimethyl Sulfoxide (DMSO), used to freeze stem cells.

Scientific Explanation for Smell Changes

DMSO causes a strong smell, like garlic or creamed corn, in patients. This happens because DMSO isn’t fully broken down right away. Its breakdown products cause the smell.

Key factors contributing to the smell include:

• The amount of DMSO used in the stem cell preservation process
• The rate at which the patient’s body metabolizes DMSO
• Individual differences in patient physiology and metabolism

Types of Odors Patients Report

Patients smell a range of things, from garlic to creamed corn. The smell’s strength and how long it lasts can differ a lot.

When Smell Changes Typically Begin

Unusual smells start soon after the transplant. This is when the body starts to break down DMSO. It usually happens in the first days or weeks.

Patient Descriptions of the Experience

Patients find the smell surreal and sometimes upsetting. Some say it’s always there, while others feel it comes and goes. They’ve said things like, “It smelled like garlic in my body,” or “I smelled like creamed corn all the time.”

Understanding these smell changes can help patients feel better. It can make their transplant experience less stressful.

Duration of Smell Changes: What to Expect

The smell after a stem cell transplant can last different lengths of time. But, there are some general guidelines to help you know what to expect. The smell is often strong because of the treatment, like DMSO used in freezing stem cells.

Typical Timeline for Smell Normalization

The smell usually goes away in a few days to weeks after the transplant. But, how long it takes can depend on many things. This includes your health and the treatment you got before the transplant.

Factors Affecting Duration of Smell Changes

Several things can affect how long the smell lasts. These include the amount of DMSO used, how fast your body processes things, and how much water you drink. Drinking plenty of water can help the smell go away faster.

Patient Experiences and Variations

How long the smell lasts can vary a lot from person to person. Some might notice it fade in days, while others might take weeks. Keeping a journal of your symptoms can help you see patterns and track how you’re doing.

When Smell Changes Become Concerning

If the smell lasts longer than expected or comes with other worrying symptoms, see your doctor. It’s important to know the difference between normal side effects and serious problems. Your doctor can offer advice and help manage any issues.

Knowing what to expect with smell changes after a stem cell transplant can help. It can make your experience better. Being informed can help you deal with this side effect more easily.

Causes of Smell Changes After Stem Cell Transplants

The sense of smell can change a lot after a stem cell transplant. It’s important to know why this happens. Many patients who get stem cell transplants notice changes in their smell.

Medication-Related Causes

Medications used during and after the transplant can affect smell. Some drugs, like those in chemotherapy, can change how we taste and smell. DMSO (Dimethyl Sulfoxide) can make some patients smell like garlic.

Cellular and Metabolic Changes

The transplant process changes the body a lot. The treatment before the transplant can cause mouth sores. This can mess with how we smell. Also, when the body starts to heal, it can affect how we sense things.

Graft-Versus-Host Disease Effects

Graft-versus-host disease (GVHD) is a problem that can happen after a transplant. It’s when the new cells attack the body. GVHD can hurt the skin, liver, and stomach, and it can change how we smell and taste.

Relationship to Other Transplant Complications

Smell changes can also be linked to other transplant problems. Things like infections and organ issues can affect how we smell. It’s a complex situation, and dealing with one problem can impact others.

Cause	Description	Impact on Smell
DMSO	Used in cryopreservation of stem cells	Garlic-like odor
Medication	Chemotherapy and immunosuppression drugs	Alters taste and smell
GVHD	Graft-versus-host disease	Affects various bodily functions, including smell

The Bone Marrow Transplant Recovery Timeline

Knowing the bone marrow transplant recovery timeline is key for patients and their caregivers. The journey after the transplant is long and has many stages. Each stage has its own challenges and important moments.

First 30 Days Post-Transplant

The first 30 days after a bone marrow transplant are very important. Patients are watched closely for any signs of trouble, like infections or graft-versus-host disease (GVHD). Their immune system is very weak, so keeping things clean and following medication closely is vital.

• Close monitoring for infection and GVHD
• Strict adherence to medication
• Limited contact with others to prevent infection

Days 30-100: Critical Recovery Period

Between days 30 and 100, doctors keep a close eye on how the patient is doing. This time is key for the new bone marrow to take hold and for the immune system to start healing.

“The period between 30 to 100 days post-transplant is a critical phase where the patient’s immune system starts to recover, and the risk of infections begins to decrease.”

The Significance of Day 100 After Bone Marrow Transplant

Day 100 is a big milestone in recovery. By then, many patients have made a lot of progress, and their immune systems are getting back to normal. But, it’s also when some transplant side effects might start to show up.

Long-term Recovery Expectations

After Day 100, patients start the long-term recovery phase. While many can go back to their usual lives, others may face lasting effects from the transplant. It’s important to keep up with follow-up care to watch for any late problems and manage ongoing issues.

Recovery times can differ a lot from person to person. Things like the patient’s health before the transplant, the type of transplant, and any complications can affect how long it takes to recover.

Managing and Coping with Smell Changes

After a stem cell transplant, managing smell changes is key. Patients might smell things that are unpleasant. It’s important to find ways to cope with these changes to improve life quality during recovery.

Practical Tips for Daily Living

There are many ways to manage smell changes. Sucking on hard candy or chewing sugar-free gum can mask bad smells. Keeping a journal to track smell changes can help find patterns or triggers.

Using aromatherapy or inhaling peppermint can offer relief. Good oral hygiene and mouthwash use can also reduce bad tastes and smells.

Dietary Adjustments That May Help

Changing your diet can help manage smell changes. Eating small, frequent meals can help with nausea and smell intensity. Avoiding strong-smelling foods like fish or garlic is also good.

Eating bland foods like crackers or toast can stabilize your sense of smell. Drinking plenty of water is also important for staying hydrated.

Environmental Modifications

Changing your environment can also help. Using exhaust fans while cooking and avoiding strong-smelling cleaning products can reduce bad odors.

Keeping your living space well-ventilated and using air purifiers can also help. Some find that using unscented personal care products reduces irritation from fragrances.

When to Seek Medical Attention

Some smell changes are temporary, but knowing when to seek medical help is important. If smell changes are persistent or severe, or if they come with other symptoms, seek medical help.

Talking to your transplant team about changes in smell perception can help find underlying issues. Keeping a detailed record of symptoms is helpful in these discussions.

Other Sensory Changes Following Transplantation

After a transplant, you might notice big changes in how you sense the world. These can affect your smell, taste, vision, and hearing. Such changes can really impact your life and how you feel.

Taste Alterations and Their Connection to Smell

Many people notice changes in their taste after a stem cell transplant. Taste and smell are closely tied. So, if one changes, the other might too. You might taste things differently, like a metallic taste, or find it hard to taste some foods.

The link between taste and smell is deep. When your sense of smell changes, it can change how food tastes. This means that smell changes can lead to taste changes, and vice versa.

Visual and Auditory Changes

Some people see things differently after a transplant. You might notice blurry vision, dry eyes, or be more sensitive to light. These changes can be due to the treatment or medicines used during the transplant.

Changes in hearing, like tinnitus or hearing loss, can also happen. These might be short-term or last longer. It’s important to tell your doctor if you notice any hearing or vision changes.

How Sensory Changes Affect Quality of Life

Sensory changes can really affect your daily life. For example, taste changes can make eating less enjoyable and affect your nutrition. This can lead to weight loss or malnutrition.

Changes in vision or hearing can also make everyday tasks harder. They can affect how you interact with others. Knowing about these possible changes can help you and your caregivers prepare and cope better.

Sensory Change	Possible Effects	Coping Strategies
Taste Alterations	Changes in appetite, nutrition	Experiment with different flavors, avoid strong-smelling foods
Visual Changes	Difficulty reading, sensitivity to light	Use sunglasses, adjust lighting at home
Auditory Changes	Hearing loss, tinnitus	Use ear protection, consider hearing aids

Medical Interventions for Persistent Smell Issues

For some, smells after a stem cell transplant don’t go away. This means they need medical help. Knowing when and how to get help is key to better living for those who have had a transplant.

When Intervention Becomes Necessary

Medical help is needed when smells bother a patient’s daily life or show a problem. It’s important to know the difference between normal changes and ones that need a doctor. Look out for signs like smells that don’t go away or are very strong.

Available Treatments and Therapies

There are many ways to fix smell problems. Doctors might give medicines to help, like antibiotics for infections or drugs to stop GVHD. Some people find help in smelling different things to get their sense of smell back.

One patient said, “I had a metallic smell after my transplant. My doctors and I found a way to manage it with medicine and what I ate.”

“The smell was like nothing I’d ever experienced before. It was as if everything tasted and smelled like metal.”

Effectiveness of Medical Interventions

How well treatments work can differ. Some people get a lot better, while others see small changes. It’s important to work with your doctor to find the best treatment for you.

Experimental Approaches

Scientists are always looking for new ways to deal with smell problems after a transplant. They’re trying new medicines, therapies like acupuncture, and better ways to train the sense of smell. Keeping up with the latest research and trials can give patients more ways to handle their symptoms.

The Psychological Impact of Transplant-Related Sensory Changes

After a transplant, patients face big emotional and psychological hurdles. Changes in smell can be really tough and impact many parts of their life.

Emotional Responses to Smell Alterations

Patients react differently to smell changes. Some get frustrated because they can’t enjoy foods or scents they used to love. Others feel anxious about what these changes mean for their health.

These feelings can really change a patient’s life. It’s key for doctors to understand and help with these issues.

Effects on Appetite and Nutrition

Changes in smell can mess with a patient’s appetite and nutrition. Smell is key to taste, so smell changes can make food less appealing. This might lead to not eating enough.

Working with a dietitian can help. Patients should talk to their healthcare team about making a meal plan that works for them.

Social Implications

Smell changes can also affect how patients interact with others. They might stay away from meals with friends or feel shy about their smell. This can make them feel lonely.

Support groups and counseling can help. They offer a place for patients to share their feelings and get support from others facing similar issues.

Mental Health Support Options

It’s important to see the big picture of how sensory changes affect patients. There are mental health services like counseling and therapy to help them deal with these changes.

Patients should talk to their healthcare team about their emotional and psychological struggles. This way, they can get the help they need.

Communicating with Your Healthcare Team About Smell Issues

Talking to your healthcare team about smell problems after a stem cell transplant is key. It helps your recovery and well-being. Be open and detailed about any smell changes you notice.

Describing Your Symptoms Effectively

When you talk about smell issues, describe them well. Note the odors, when they happen, and what triggers or stops them.

Tips for Describing Smell Symptoms:

• Be specific about the odors you smell (e.g., metallic, sour, or burnt).
• Mention if the smells are constant or intermittent.
• Note any triggers or relievers you’ve identified.

Questions to Ask Your Transplant Team

Having a list of questions for your transplant team helps you understand your condition. It also helps manage your symptoms better.

Question Category	Example Questions
Causes and Effects	What could be causing my smell disturbances? How might these changes affect my overall health?
Management and Treatment	Are there any treatments available for smell disturbances? How can I manage these symptoms on a daily basis?
Monitoring Progress	How often should I report changes in my smell perception? What signs indicate that I should seek immediate medical attention?

Creating a Symptom Journal

Keeping a symptom journal is helpful. It tracks your smell disturbances and other symptoms. This helps your healthcare team understand you better.

Include the following in your symptom journal:

• Date and time of smell disturbances.
• Description of the odors.
• Any triggers or relievers.
• Other symptoms you’re experiencing.

When to Report Changes in Smell Perception

Knowing when to report smell changes to your healthcare team is important. If you notice big changes, like a bad smell or losing your sense of smell, call your doctor.

When to Seek Immediate Attention:

• Sudden or severe changes in smell.
• Smell disturbances with other concerning symptoms.
• Uncertainty about managing your symptoms.

Conclusion: Living with and Beyond Transplant-Related Smell Changes

Dealing with smell changes after a transplant can be tough. But knowing these changes usually go away can help. The smell from stem cell transplants, like the DMSO smell, can be strong. Yet, most people find it fades with time.

Handling these changes takes time and smart strategies. Knowing why smells change and how they link to transplants helps a lot. With tips for daily life, diet changes, and making your environment better, life can get much better.

After the transplant, the goal is to keep improving and dealing with any lasting smell issues. With the right help and care, people can get past these smell challenges. This way, they can feel better overall.

FAQ

Reference

1. Sorensen, B., Winge, P., Nielsen, J. B., & Wendelbo, Ø. (2019). Adverse reactions of dimethyl sulfoxide in humans: a systematic review. PMC. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6707402/