Health at 23andMe: What Can You Learn?

Editor’s note: Pending an FDA decision, 23andMe no longer offers new customers access to health reports referred to in this post. Customers who received their health information prior to November 22, 2013 will still be able to see their health reports, but those who purchased after that time will only have access to ancestry information as well as access to their uninterpreted raw data. These new customers may receive health reports in the future dependent on FDA marketing authorization.
If you’re exploring your 23andMe Health results for the first time, the sheer amount of information may seem overwhelming. There are nearly 200* reports connecting your genetics to various health conditions and traits. There is an active community of other customers asking and answering questions related to health. And if you love details, there’s also a tool for browsing your raw data — all of the hundreds of thousands of locations in your genome that we’ve determined from your sample.

So where do you start? This is a personal choice, one that is often directed by questions you may already have about diseases that run in the family or that you’re interested in for other reasons. But whether you have a set of health topics in mind or not, it may help to know what 23andMe offers the curious individual. With this series of posts on Health at 23andMe, I’ll lay out the landscape of 23andMe’s health service, dissect different types of health reports, and answer some frequently asked questions, using some of my own results as examples.

Before we get into the details of the different types of health content available to 23andMe customers, it may be helpful to review what exactly 23andMe determines from your saliva sample.

All of us have a genome made up of DNA. DNA itself is made up of individual molecules called nucleotides, which can come in four types designated by the letters ‘A’, ‘G’, ‘T’, and ‘C’. These nucleotide letters are connected together in long, linear sequences of DNA, spelling out genes and other important instructions along the way. Each of our chromosomes consists of such a sequence of DNA, millions of nucleotides in length. And since we have two copies of each chromosome — one from dad and one from mom, except for the X in males — we have two letters at each location in the genome (a “genotype”).

If you compare the sequences of letters between two people, you’ll find that they are over 99% identical. But there are places where the letters might be different. Some of these differences are large — chunks of letters are missing or duplicated, for example — or they can be different at just a single letter location, an ‘AA’ genotype in one person vs. ‘AC’ in another. These single letter differences can be quite common, and what 23andMe does is determine your genotype at hundreds of thousands of these commonly variable sites, called single nucleotide polymorphisms (SNPs).

Researchers have been studying SNPs (pronounced “snips”) and their impact on human health for many years now, and some links are well-established. For example, a number of SNPs located in genes involved in the immune system have been associated with multiple autoimmune conditions such as rheumatoid arthritis and lupus. There are also many SNPs that have been associated with common cancers of the breast and prostate. But for the most part, the effect that each of these SNPs has on disease risk is small — usually modifying risk about 1-2 times compared to average.

23andMe also determines your genotypes for a number of locations where variation is much more rare and having two copies of the rare version has direct implications for disease. These are included in a number of reports under “Carrier Status” category.

Indeed, for those who don’t have specific health topics in mind but wish to explore their health content methodically, 23andMe classifies its health reports into four different categories*, each dealing with a different area of health information:

Disease Risk. Most diseases are complex, meaning many factors — both genetic and non-genetic — affect whether someone develops the disease. These reports include information on some of the known genetic factors associated with various diseases, and how your own genetics influences your risk. This category includes conditions like Type 2 Diabetes, Prostate Cancer, and Atrial Fibrillation.
Inherited Conditions (Carrier Status). Some diseases are directly caused by rare genetic variants — known as mutations in this context — in specific genes. Because two copies of a mutation are usually required to cause the disease, people with one copy usually don’t have the disease, but are called “carriers”. Our reports on Inherited Conditions will tell you whether you carry some of the more common mutations known for certain diseases. This information is especially relevant to individuals planning to have children. This category includes conditions like Cystic Fibrosis, Tay-Sachs Disease, and Sickle Cell Anemia.
Drug Response. Different people respond to drugs in different ways, and this is at least partly due to genetics. These reports include information on how your genetics may influence your sensitivity to a drug, risk of side effects, or general effectiveness. This category includes Warfarin Sensitivity, Fluorouracil Toxicity, and Response to Hepatitis C Treatment.
Traits. Eye color, hair color, whether you flush when you drink alcohol: these are all familiar things we can easily see or discern. But some traits may not be so familiar — for example, did you know that some people detect a distinct smell in their urine after eating asparagus? (Hint: it has something to do with genetics!) Other reports in this category include Lactose Intolerance, HDL Cholesterol Levels, and Male-Pattern Baldness.

Other posts in this series walk through results for these different categories and explain how to navigate each type of health report.

More Health at 23andMe posts:
Navigating Your Health ResultsAnatomy of a 4-Star Disease Risk ReportWhat’s Your Status?- (Carrier status for Inherited Conditions)When One Size Doesn’t Fit All – (the genetics of Drug Response)The Circus of Human Traits

For a refresher course on genetics or help navigating the service, visit Genetics 101 on our website, or see our Frequently Asked Questions.

Check out our companion series, Ancestry at 23andMe, and other articles in 23andMe How-To.

* Based on current products and services. Exact details subject to change.


  • Scott23H

    Emily, Yes all of those are now under the umbrella of health reports.

  • Paul D

    I purchased my kit in October of 2013, but the 23andme lab did not start processing my DNA sample until November 27th. Does this mean I will not get the full report I was expecting? When I purchased my kit, I had no idea about the pending litigation between 23andme and the FDA, and feel I should be provided a full report on what my DNA has to tell.

    • Scott23H

      If you purchased your kit before Nov. 22 you will still get both your health and ancestry results. So in your case the answer is yes you will get your health results.

      • Paul D

        Thanks Scott, That is good news. From some of the stuff on the web site it is hard do deduce if that was indeed a fact. Now I know for sure!

  • Loni

    If we purchase now and don’t get the interpretation of the results, is the cost the same or less than (prior to November 27) when you were able to purchase with the full report/interpretation? Seems it should be considerably less now without that useful interpretation data. ‘And wondering if if would then be worth waiting it out to get FDA to approve, if they will, and get the full deal if it is same cost ????

    • Scott23H

      Loni, Thanks for the note. The cost is the same. As we work through the process with the FDA we may again look at the cost structure, but at the moment the amount of work to process the kit and run the analysis is the same. Hope that helps in your decision making. Thanks.

  • Scott23H

    Michael, It will be difficult for you to create a family tree since you are adopted. If you connect with DNA relatives through 23andMe you may be able to fill in more of your family tree however. If you have additional information about your biological family — names for instance — that might also help in your search. Best of luck.

  • Lori Halstead

    Hi, my mother purchased the kit for me as a surprise on November 6th. She gave it to me on Christmas and I put it in the mail on the December 27th. Since she purchased before November 22nd, will I still receive the health related info? I’m assuming purchase date is known from the bar code. Thank you

    • Scott23H

      Yes, If the kit was purchased before the 22nd of November you’ll get your health results.

  • Stacy Clarkson

    A question as a white guy with west European ancestry that has not gotten his results back,how much Neanderthal can I expect to be????

    • Scott23H

      There is typically a range of from 1 to 4 percent, but on average you would expect about 2.8 percent.

  • Stacy Clarkson

    Is that above average,for what I assume is a white person???

  • Scott23H

    Derek,
    Thanks for the question. I think it has come up before from other customers outside of the US. The answer is no, we won’t be handling international customers differently, so your Canadian family members won’t be able to get health results if they’ve purchased after November 22, 2013. We hope to get through this FDA process as quickly as possible but as yet do not know when customers will again be able to return health results to customers.

  • Kevin Porter

    I purchased my kits on November 18th. Will I be able to get the health results?

    • Scott23H

      Kevin, The answer is yes. If you purchased before the 22nd of November, you will get your health results as well as your ancestry results.

  • Betty Byrum

    We just got Mom’s results from 23andme and we know for a fact that she is part Native American, yet nothing showed in the results. In fact, it showed her as 99.9% European. Why did that happen? Could it be a mistake?

    • Scott23H

      Betty,
      Currently 23andMe has several features that can reveal genetic evidence of Native American ancestry, although they are not considered a confirmatory test or proof of such ancestry in a legal context.
      It is important to note that sometimes, even if a person’s great, great grandmother, for instance, was considered to be Native American, the DNA does not reveal the Native American ancestry because evidence is lost each generation. In general, however, Native American ancestry within the last few generations is likely to reveal itself through our features.

  • Eileen Wargula

    I bought my kit prior to the restrictions but didn’t turn it in until a week or so ago. Are you guys sure I will get all my results since I purchased before all this mess started? Thanks so much

    • Scott23H

      The date of purchase is what is controlling Eileen, so even though you’ve only just now sent it in, if the kit was purchased prior to the November 22nd letter from the FDA then you will get health results as well as ancestry results.

  • Scott23H

    Your Ancestry Composition gives you information about your more recent ancestors. If you are looking at a 1 percent that translates into about 200 years. When you get below 1 percent it is much harder to make an estimate. It’s not going back 500 or 5000 years however. One caveat with percentages below 1 percent is that it is within margins of error. That doesn’t mean that those are not real signals, it just means that you should look for other confirming information. It may be difficult for you to get that since your father has passed away.
    The “unassigned” percentage is normal and actually very low. This is a function of our model. We want to be conservative in making assigning ancestry. In some cases when we are dealing with someone with ancestry from populations that do not have a lot of reference data, like Native Americans, it’s more difficult to make an estimate.
    That gets us to your last question regarding your mother. Yes, if she were tested you could see a split view of your Ancestry Composition and see which segments came from your mother and which came from your father. That would help a lot in finding out more detail about your Native American ancestry.

    • Martha

      Thanks so much for taking the time to help me!

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