You cannot change the DNA you were born with, but scientists can edit genes in cells and embryos in a lab

Your DNA is the instruction set your cells follow. Once you are born, the DNA in your existing cells stays the same for life — your body does not rewrite it on its own. However, scientists have developed tools that can alter DNA in laboratory settings, and some of these tools are being tested in people with serious genetic diseases. The difference matters: editing genes in a lab is not the same as changing the DNA throughout your whole body, and it is not something you can do at home or through a medical office visit like a vaccine.

The most well-known gene-editing tool is called CRISPR, which works like molecular scissors. Researchers can use it to cut out a faulty gene instruction and replace it with a corrected version. In a lab, this works. In a living person, the challenge is getting the tool into enough cells to make a difference, and making sure it does not cut the wrong spot by accident.

Key Takeaways

  • Gene editing tools like CRISPR can alter DNA in laboratory cells and in some medical treatments, but they cannot change all the DNA in your body after birth.
  • The only way to change DNA that gets passed to your children is to edit embryos before pregnancy, which is illegal in most countries and available nowhere as a standard medical treatment.
  • Gene therapy — injecting edited cells or tools into a patient — is real but extremely limited; it works only for a few rare diseases and requires approval from the FDA or similar bodies.
  • Changing your DNA through diet, exercise, supplements, or lifestyle does not happen; these things change how your genes are expressed, not the genes themselves.

How gene editing works in a laboratory

Scientists can edit DNA in cells grown in a dish. They use CRISPR or other tools to find a specific gene, cut it, and insert a corrected version. This happens outside the body, in controlled conditions. The edited cells can then be studied, grown in larger numbers, or — in some cases — put back into a patient.

The process is precise in a petri dish but much harder in a living person. Your body has trillions of cells. Editing genes in a few thousand of them will not cure a disease that affects your whole body. Researchers have to find a way to deliver the editing tool to the right cells, make sure it works, and confirm it does not damage anything else. For some blood disorders and certain eye diseases, this is now possible. For most conditions, it is still experimental.

Gene therapy: editing cells and returning them to your body

One approach that has moved beyond the lab is gene therapy. In this method, doctors remove some of your cells, edit them in a laboratory, and then put the corrected cells back into your body. Your own immune system recognizes them as yours, so they can survive and do their job.

This has worked for a small number of diseases. The FDA has approved gene therapies for certain inherited retinal diseases (which cause blindness), spinal muscular atrophy (a muscle-wasting disease), and a few blood disorders. Each approval took years of testing and costs hundreds of thousands of dollars. The treatment is not available for common conditions like heart disease, diabetes, or obesity.

Even when gene therapy is approved, it is not a straightforward procedure. You will need genetic testing to confirm you have the specific mutation the therapy targets. The treatment itself may require hospitalization. Side effects can be serious. It is reserved for people with severe, life-threatening conditions where other treatments have failed.

Editing embryos and the legal and ethical limits

The only way to change DNA that your children will inherit is to edit an embryo — a fertilized egg — before pregnancy begins. Scientists can do this in a laboratory. In 2018, a researcher in China created the first gene-edited babies, which caused international outrage. He edited embryos to try to make them resistant to HIV, and the experiment was widely condemned as reckless and unethical.

Most countries have banned or heavily restricted embryo editing. In the United States, federal funding cannot be used for it, and many states have laws against it. Even where it is not explicitly illegal, no clinic offers it as a service. The scientific community has called for a global moratorium on editing embryos for traits like intelligence or appearance, though research on editing embryos to prevent serious diseases continues in some countries under strict oversight.

Why diet, exercise, and supplements do not change your DNA

You may have read that certain foods or practices can "change your DNA" or "set up" genes. This is misleading language. What actually happens is called epigenetic change — your DNA sequence stays the same, but chemical tags on top of your genes turn them up or down, like adjusting the volume on a speaker without changing the song.

Exercise, sleep, stress reduction, and diet can influence these tags. A person who exercises regularly may have different epigenetic patterns than someone who is sedentary, and this can affect how their genes are expressed. But the underlying DNA code is identical. If you stop exercising, the epigenetic changes can reverse. And epigenetic changes do not get passed to your children in most cases — your children start with their own fresh set of tags based on their own environment and choices.

This distinction matters because it affects what you should expect. Changing your lifestyle can improve your health and may reduce your disease risk, but it will not fix a genetic mutation that causes a disease. A person born with cystic fibrosis will not cure it through diet. A person with a BRCA mutation that increases cancer risk will not eliminate that risk through exercise, though exercise may improve their overall health.

Somatic gene therapy versus germline editing

Somatic gene therapy edits cells in your body that are not reproductive cells. Changes made to somatic cells affect only you and do not pass to your children. This is the type of gene therapy currently approved by the FDA. It is less ethically fraught than editing embryos because it affects only the person being treated.

Germline editing means editing reproductive cells or embryos, so the changes would be inherited by future generations. This is where most of the ethical and legal restrictions come in. Even if the science were perfect, changing the human gene pool raises questions about consent, equity, and what counts as a disease worth editing versus a normal human variation.

What gene editing cannot do right now

Gene editing cannot make you taller, smarter, or stronger. It cannot change your eye color or hair color after birth. It cannot cure common diseases like diabetes or heart disease — these involve hundreds of genes and environmental factors, not a single faulty instruction. It cannot be done at home, ordered online, or administered by a regular doctor.

The tools exist in research labs and in a handful of approved medical treatments for rare genetic diseases. The gap between what is theoretically possible and what is actually available to patients is enormous. A person reading about CRISPR breakthroughs should not expect those breakthroughs to become a treatment they can receive anytime soon, if ever.

Frequently Asked Questions

Can I change my DNA to prevent a disease I might inherit?

If you carry a gene mutation that causes a disease, you cannot change your own DNA to remove it. However, if you are planning to have children, you could pursue preimplantation genetic testing — creating embryos through in vitro fertilization, testing them for the mutation, and implanting only the unaffected ones. This is legal in most countries and available at fertility clinics, though it is expensive and not covered by most insurance.

Does CRISPR work on humans right now?

CRISPR has been used in clinical trials for a few rare blood disorders and eye diseases, with some positive results. But it is not a standard treatment you can request from your doctor. It is available only through research studies or, in rare cases, through FDA-approved therapies for specific conditions. Most people will never have access to it.

If I change my lifestyle, will my children inherit those changes?

Your children will inherit your DNA, not your lifestyle. However, some research suggests that extreme stress, starvation, or other severe conditions during pregnancy may cause epigenetic changes that affect a fetus. In normal circumstances, your children start with their own fresh epigenetic patterns and will develop their own based on their own environment and choices.

Can gene therapy cure genetic diseases?

Gene therapy has cured or significantly improved a small number of rare genetic diseases in clinical trials and approved treatments. It does not work for most genetic conditions. Even when it does work, it is expensive, requires careful genetic testing to confirm you have the right mutation, and may have serious side effects.

Is it illegal to edit your own DNA?

There is no law against editing your own cells in a laboratory if you have the equipment and knowledge. However, using gene-editing tools on yourself or others without medical oversight is extremely dangerous and could cause serious harm. Gene therapy and clinical trials are heavily regulated to protect patients from injury.