At My Forever DNA, we understand how crucial accuracy and reliability are, whether you’re taking a paternity test, sibling test, or an early gender DNA test. One of the most common questions we receive is:

"Can medical treatments like chemotherapy, blood transfusions, or drug use affect my DNA or interfere with DNA test results?"

It’s a smart question - especially if you or a loved one has undergone treatments that may impact the body. 

Here’s what you need to know:

Does Your DNA Ever Change?

Your DNA is your body’s permanent instruction manual. It’s set at conception and remains the same in every cell throughout your lifetime. While certain factors can influence how your DNA is expressed (called epigenetics), the actual genetic code - the part we analyze for DNA testing - does not change.

That means your DNA results are stable and accurate, regardless of age, lifestyle, or most external influences.

Can Blood Transfusions Affect DNA Test Results?

If you’ve had a recent blood transfusion, you might be wondering if it could interfere with your DNA results. In most cases, the answer is no.

Why? Red blood cells - the ones typically used in transfusions - don’t contain DNA, because they lack nuclei. Even if white blood cells are present in small amounts, they typically don’t affect a buccal (cheek) swab.

Exception: Large-scale transfusions involving white blood cells (like those in a bone marrow transplant) may introduce donor DNA into your bloodstream temporarily. But this is rare and not a concern for standard transfusions.

Bone Marrow Transplants and DNA Testing

Bone marrow transplants are unique in that they replace your blood-forming stem cells with those of a donor. After the transplant, your blood - and sometimes other tissues -may carry the donor’s DNA.

But here’s the good news: accurate testing is still possible.

If you’ve had a bone marrow transplant, a cheek swab may contain mixed DNA from both you and your donor. While this can occasionally lead to unclear results, it doesn’t mean DNA testing isn’t an option.

Instead, we recommend using an alternative DNA sample such as:

• Hair (with the root attached)

• Nail clippings

• A used toothbrush

These sources typically contain your original DNA, not the donor's, which allows us to provide reliable and trustworthy results.

Our team is always happy to help you determine the best collection method based on your unique situation.

Does Cancer or Chemotherapy Change DNA?

Cancer doesn’t change your inherited DNA - it results from mutations in specific cells. When we test DNA, we’re analyzing the stable, genetic code you were born with.

Chemotherapy and radiation target fast-dividing cells, and while they may affect sample quality, they do not alter your DNA sequence.

As long as we receive a viable sample - such as a cheek swab or discreet sample like toothbrush bristles or hair - our lab can deliver accurate and reliable results, even during cancer treatment.

Lifestyle, Environment, and Drug Use

Environmental exposures (like smoking, sun, or pollution) and lifestyle factors can impact gene expression, but they don’t rewrite your DNA.

Likewise, recreational or prescription drug use doesn’t alter the DNA we analyze. These substances may affect cellular health or gene expression, but the genetic code used in testing remains unchanged.

Can DNA Test Results Be Trusted Over Time?

Yes. Your DNA remains the same from birth through life. It’s one of the reasons why DNA testing is such a trusted method for identity and relationship confirmation.

Medical treatments may influence the collection method or type of sample needed, but they don’t affect the DNA itself.

Reliable DNA Results - No Matter Your Medical History

At My Forever DNA, we use advanced laboratory processes and partnerships with a U.S.-based, AABB Accredited lab to ensure high-quality results, even in complex medical situations.

If you have a unique medical history or have undergone treatments like a bone marrow transplant, contact us directly at 402-800-7161. We’ll guide you to the best collection method for your situation and ensure you receive results you can trust.

Trusted DNA Testing for Every Stage of Life.
Accurate. Private. Personalized.