In This Guide
1. You Downloaded Your Raw DNA File -- Now What?
Millions of people have taken consumer DNA tests through services like 23andMe, AncestryDNA, and TellmeGen. Most look at their ancestry breakdown, maybe check a few trait reports, and then never think about their data again. But that raw data file sitting in your downloads folder? It contains hundreds of thousands of genetic markers that can reveal meaningful information about your health, nutrition needs, and exercise response.
The problem is that raw DNA data files look intimidating. Open one and you will see row after row of letters and numbers that seem impossible to decipher. This guide changes that. By the end, you will understand exactly what each column in your raw data file means, how to look up specific genetic variants, and what to do with the information you find.
Whether you took your test for ancestry, health curiosity, or wellness optimization, your raw data is a goldmine of actionable insights -- if you know how to read it. Let us walk through it together.
2. Understanding Your Raw Data File Format
When you download your raw DNA data, you get a plain text file (usually .txt or .csv) that is typically between 15 and 25 megabytes. Inside, after a few header lines, you will find hundreds of thousands of rows. Each row represents a single SNP (Single Nucleotide Polymorphism) -- a specific position in your genome where humans commonly vary.
While the exact format varies slightly between providers, every raw data file contains the same four essential columns:
| Column | Example | What It Means |
|---|---|---|
| rsID | rs1801133 | The unique identifier for this SNP in global databases. Think of it as a serial number for this specific position in the human genome. The "rs" stands for "reference SNP." |
| Chromosome | 1 | Which of your 23 chromosome pairs this SNP lives on (1-22 for autosomes, X or Y for sex chromosomes). |
| Position | 11856378 | The exact base-pair coordinate on that chromosome. Combined with the chromosome number, this pinpoints the exact location in your genome. |
| Genotype | AG | Your actual result at this position: the two letters represent the allele you inherited from each parent (one from your mother, one from your father). |
What a Raw Data File Actually Looks Like
# rsid chromosome position genotype
rs1801133 1 11856378 AG
rs2228570 12 48272895 CT
rs762551 15 75041917 AA
rs9939609 16 53820527 AT
rs1815739 11 66560624 CC
rs429358 19 45411941 TT
This example shows six SNPs. Each line tells you: which variant (rsID), where it is (chromosome and position), and what you have (genotype). A typical file contains 600,000 to 900,000 of these lines.
3. How to Download Raw Data from 23andMe, AncestryDNA, and TellmeGen
Before you can interpret your results, you need the raw data file. Here is exactly how to download it from the three major providers:
23andMe
- 1Log in to your 23andMe account at you.23andme.com
- 2Navigate to Settings (gear icon in the top right)
- 3Scroll down to 23andMe Data section
- 4Click Download Raw Data and confirm your identity
- 5You will receive an email with a download link (usually within minutes)
File format: .txt file, tab-separated, approximately 600,000+ SNPs
AncestryDNA
- 1Log in to your Ancestry account at www.ancestry.com
- 2Go to DNA tab, then click Settings
- 3Scroll to Download Raw DNA Data
- 4Confirm your identity and click Confirm & Download
- 5Check your email for the download link (may take up to 30 minutes)
File format: .txt file, tab-separated, approximately 700,000+ SNPs
TellmeGen
- 1Log in to your TellmeGen dashboard at dashboard.tellmegen.com
- 2Navigate to Settings or Raw Data section
- 3Click Download Raw Data
- 4Verify your identity if prompted
- 5Download the file (available immediately in most cases)
File format: .csv file, comma-separated, approximately 750,000+ SNPs
Tip: Your raw data file is typically between 15-25 MB when uncompressed. Some providers deliver it as a .zip file. Extract it before uploading to any analysis tool. Store a backup copy in a secure location -- you only need to take the test once since your DNA does not change.
4. What Is a Genotype? Understanding AA, AG, GG Notation
The genotype column in your raw data is where your actual genetic information lives. Each genotype consists of two letters because you have two copies of almost every gene -- one inherited from your biological mother and one from your biological father.
The letters represent the four DNA bases: A (adenine), T (thymine), C (cytosine), and G (guanine). At any given SNP position, you might see combinations like AA, AG, GG, CT, TT, and so on.
Homozygous (Same Letters): AA, GG, TT, CC
When both letters are the same, you are homozygous at that position. Both parents gave you the same allele. This means you have two copies of that variant. If it is the common allele, this is called homozygous normal. If it is the variant allele, this is homozygous variant (which usually has a stronger effect than carrying one copy).
Heterozygous (Different Letters): AG, CT, AT
When the letters differ, you are heterozygous -- you inherited one copy of each version. For many health-related SNPs, being heterozygous produces an intermediate effect. For example, a heterozygous MTHFR carrier has about 35% reduced enzyme activity, while homozygous variant carriers have about 70% reduction.
The "--" (No Call) Result
Occasionally you will see "--" instead of two letters. This means the genotyping chip could not determine your genotype at that position. This is called a no-call and happens in roughly 1-3% of SNPs. It does not mean anything is wrong with your DNA -- the assay simply could not read that particular spot reliably.
Real-world example: For the MTHFR gene (rs1801133), the common genotype is CC (normal folate metabolism). The variant genotypes are CT (one risk allele, ~35% reduced function) and TT (two risk alleles, ~70% reduced function). If your raw data shows "CT" for rs1801133, you carry one copy of the variant and may benefit from methylfolate instead of standard folic acid.
5. Risk Alleles Explained: What "Risk" Actually Means in Genetics
The word "risk" in genetics is one of the most misunderstood terms in consumer DNA testing. When researchers label an allele as a "risk allele," they are making a statistical statement about populations, not a prediction about you as an individual.
What "Risk" Actually Means
Having the FTO risk allele does not mean you will be overweight. It means that in large population studies, people with this allele had a statistically higher average BMI. Your individual outcome depends on dozens of other factors.
A typical wellness-related SNP might increase risk by 10-30%. That is meaningful for population-level research but does not dictate your individual outcome. Two copies of the FTO risk allele, for instance, are associated with an average of roughly 3 kg (6.6 lbs) higher body weight -- not a guaranteed outcome.
Research consistently shows that healthy habits -- diet, exercise, sleep, stress management -- can offset most common genetic risk factors. The FTO obesity risk, for example, is reduced by roughly 40% with regular physical activity.
Most genetic studies have been conducted primarily in European populations. A variant labeled "risk" may have different effects in different ethnic groups. This is an important limitation of current genetic research.
Key takeaway: Think of risk alleles as road signs, not roadblocks. They tell you which areas of your health are worth paying closer attention to -- not which outcomes are predetermined. A "risk" variant for vitamin D deficiency means you should monitor your vitamin D levels more carefully, not that deficiency is inevitable.
6. How to Look Up Specific SNPs
Every health-relevant SNP has an rsID (reference SNP identifier) assigned by the National Center for Biotechnology Information (NCBI). This is your key to finding published research about any variant in your raw data.
Step 1: Find the rsID in Your Raw Data
Open your raw data file in a text editor or spreadsheet program. Use the search function (Ctrl+F or Cmd+F) to find a specific rsID. For example, search for "rs1801133" to find your MTHFR result. The genotype column will show your result (e.g., CC, CT, or TT).
Step 2: Look Up the rsID in a Database
The most reliable source is dbSNP (ncbi.nlm.nih.gov/snp/) maintained by the NCBI. Enter the rsID and you will find the chromosome location, allele frequency across populations, and links to published research. SNPedia (snpedia.com) is another popular community resource that provides plain-language summaries of what each SNP does.
Step 3: Identify Which Allele Is the Variant
Each SNP has a reference allele (the most common version) and one or more alternate alleles (the variant). The database entry will tell you which is which. If your genotype contains the alternate allele, you carry the variant. Databases also indicate allele frequency, showing you how common your genotype is in different populations.
Step 4: Read the Associated Research
For health-relevant SNPs, dbSNP links to published studies in PubMed. Look for genome-wide association studies (GWAS) and meta-analyses, as these involve the largest sample sizes and most reliable findings. Be cautious of single small studies -- replication across multiple populations is the gold standard.
Shortcut: Rather than looking up hundreds of SNPs one by one, you can upload your raw data file to an analysis platform like HOP, which automatically extracts the 20-50 most health-relevant SNPs and provides plain-language interpretations backed by published research.
7. The Most Important Health SNPs to Check First
Your raw data file contains hundreds of thousands of SNPs, but only a few dozen are well-studied enough to provide reliable wellness guidance. Here are the six that most people check first, along with what to search for in your raw data file.
For a deeper dive into what each of these variants means for your supplements, diet, and exercise, see our companion article: DNA Analysis for Health: How Genetic Testing Improves Wellness Recommendations.
MTHFR
Search: rs1801133
Controls folate (vitamin B9) metabolism. Roughly 40% of people carry a variant. Look for your genotype: CC = normal, CT = one variant copy, TT = two variant copies.
Impact: Supplement form selection (methylfolate vs folic acid)
VDR
Search: rs2228570
Vitamin D receptor efficiency. Determines how well your cells respond to vitamin D regardless of blood levels. Variants may require higher supplementation doses.
Impact: Vitamin D dosing and monitoring frequency
APOE
Search: rs429358 + rs7412
Affects cholesterol processing and cardiovascular risk. The e4 variant is associated with higher LDL, while e2 tends to be protective. Requires checking two SNPs together to determine your APOE type (e2/e3/e4).
Impact: Dietary fat choices and lipid monitoring
CYP1A2
Search: rs762551
Caffeine metabolism speed. AA = fast metabolizer (coffee may be beneficial). AC or CC = slow metabolizer (caffeine stays in your system longer, higher cardiovascular risk from excess coffee).
Impact: Caffeine intake guidance and timing
ACTN3
Search: rs1815739
Muscle fiber composition. CC (RR) = power/sprint oriented. TT (XX) = endurance oriented. CT (RX) = mixed. Found in nearly all elite sprinters in the RR form.
Impact: Exercise type selection and training program design
FTO
Search: rs9939609
The most studied obesity-related gene. The A allele is associated with increased appetite and calorie consumption. Roughly 45% of Europeans carry at least one copy. Effect is significantly reduced by regular exercise.
Impact: Dietary strategy (high-protein for satiety) and exercise priority
8. Common Misconceptions About DNA Test Results
Consumer DNA testing has generated enormous public interest, but also widespread misunderstanding. Here are the most common misconceptions and the reality behind each:
Myth: "I have the gene FOR cancer / diabetes / obesity"
Reality: There is no single "gene for" most complex conditions. What consumer tests detect are variants that slightly increase or decrease statistical risk. Most chronic diseases involve hundreds of genes interacting with environmental factors. Having an FTO variant does not mean you "have the obesity gene" -- it means one of many factors that influence weight is slightly shifted.
Myth: "My DNA results are 100% accurate and definitive"
Reality: Consumer genotyping chips have a per-SNP accuracy of about 99.5-99.9%, which sounds excellent until you consider that your file has 600,000+ SNPs. That means a few hundred to a few thousand individual readings may be incorrect. For important health decisions, particularly around rare disease variants, clinical confirmation through a different testing method is recommended.
Myth: "If I don't have the risk allele, I'm safe"
Reality: Not having a specific risk allele does not make you immune. Consumer tests check only a fraction of all known variants, and many genetic risk factors have not yet been discovered. Furthermore, environmental factors, lifestyle choices, and random chance all contribute to health outcomes. Think of genetic risk as one input among many, not a binary on/off switch.
Myth: "Consumer DNA tests and clinical genetic tests are the same thing"
Reality: They are fundamentally different technologies. Consumer tests use genotyping arrays that check specific known positions (like reading specific pages of a book). Clinical tests often use sequencing that reads entire genes or your whole genome (reading the entire book). Consumer tests are excellent for common wellness-related variants but should not be used to rule out rare genetic conditions.
9. Limitations of Consumer DNA Testing
Understanding what consumer DNA tests cannot do is just as important as understanding what they can. Being aware of these limitations helps you interpret your results more accurately:
Coverage Gaps
Genotyping arrays check 600,000-900,000 positions out of roughly 3 billion base pairs in the human genome. That is less than 0.03% of your total DNA. Many important variants, especially rare ones, are simply not on the chip. Newer array versions improve coverage, but significant gaps remain.
Imputation Uncertainty
Some providers use a technique called imputation to infer your genotype at positions not directly tested, based on statistical patterns in nearby markers. This is scientifically valid but less accurate than direct measurement. Imputed results should be interpreted with more caution than directly genotyped ones.
Population-Specific Research Bias
As of 2026, approximately 78% of participants in genetic research studies are of European descent. This means risk calculations and effect sizes may be less accurate for people of African, Asian, Hispanic, or mixed ancestry. The field is working to close this gap, but it remains a significant limitation today.
Epigenetics Not Captured
Your raw data shows your DNA sequence but not your epigenetic modifications -- chemical tags that turn genes on or off without changing the sequence. Factors like diet, stress, sleep, and toxin exposure influence your epigenome, which can be just as important as the underlying sequence for health outcomes. Consumer DNA tests do not capture this layer.
Gene-Gene Interactions Are Complex
Most consumer interpretations look at SNPs one at a time. In reality, genes interact with each other in complex ways (called epistasis). A variant in one gene might increase risk only when combined with a specific variant in another gene. Most consumer platforms do not yet model these interactions comprehensively.
10. DNA Results Are NOT a Diagnosis
This point is critical enough to deserve its own section. Consumer DNA test results are wellness information, not medical diagnoses. Understanding the distinction can prevent both unnecessary panic and dangerous overconfidence.
| Consumer Wellness Testing | Clinical Genetic Testing |
|---|---|
| Genotyping array (checks known positions) | Sequencing (reads entire genes or genome) |
| Optimized for common variants | Detects rare and novel mutations |
| No genetic counselor interpretation | Results reviewed by genetic counselor |
| FDA classified as general wellness | FDA regulated as medical device |
| Useful for wellness optimization | Useful for diagnosing genetic conditions |
| Cost: $100-200 (one-time) | Cost: $250-10,000+ (insurance may cover) |
When to See a Genetic Counselor
If your consumer test reveals a variant associated with a serious inherited condition (such as BRCA1/2 for breast cancer, or APOE4/4 for Alzheimer's risk), do not make medical decisions based on consumer test results alone. Schedule a consultation with a certified genetic counselor who can order confirmatory clinical-grade testing, interpret results in the context of your family history, and guide appropriate next steps.
Consumer DNA testing excels at a specific use case: helping you fine-tune your wellness habits -- which supplements to prioritize, what exercise style matches your body, and which nutrients to pay extra attention to. For that purpose, the data is excellent. Just remember it is a wellness compass, not a medical crystal ball.
11. Combining DNA Insights with Bloodwork for the Complete Picture
DNA tells you about your genetic tendencies -- what your body is predisposed to. Bloodwork tells you about your current reality -- what is actually happening in your body right now. Neither alone gives you the full story. Together, they create the most complete picture available for personalized wellness.
How the Two Data Sources Complement Each Other
DNA identifies what to watch for
Your VDR variant suggests you may need more vitamin D. Your MTHFR variant suggests folate metabolism may be compromised.
Bloodwork confirms what is actually happening
Your vitamin D blood level is 22 ng/mL (low). Your homocysteine is elevated at 14 umol/L (suggesting folate cycle issues).
Combined insight drives precise action
Supplement with 4,000 IU vitamin D3 (higher dose because of VDR variant + confirmed low levels). Switch to methylfolate (because MTHFR variant + elevated homocysteine confirms the issue). Retest in 3 months.
This layered approach is what separates generic health advice from truly personalized recommendations. If you have not had blood work done recently, our complete guide to reading blood test results walks you through what to test and how to understand the results. For iron-specific guidance, see our ferritin levels guide.
Platforms like HOP automate this cross-referencing: upload your raw DNA file and your lab results, and the system scores and sorts supplement, meal, and exercise recommendations based on both your genetic profile and your current biomarker levels.
12. Next Steps: What to Do with Your Results
Now that you understand how to read and interpret your raw DNA data, here is a practical action plan:
Download and Secure Your Raw Data
If you have not already, download your raw DNA file from your testing provider using the steps in Section 3. Store a backup copy in a secure, encrypted location. You only need to take the test once.
Check the Big Six SNPs
Open your file and search for the six key SNPs covered in Section 7: MTHFR (rs1801133), VDR (rs2228570), APOE (rs429358 + rs7412), CYP1A2 (rs762551), ACTN3 (rs1815739), and FTO (rs9939609). Write down your genotype for each.
Upload to an Analysis Platform
For a comprehensive automated analysis, upload your raw data to a platform that extracts health-relevant SNPs and provides plain-language interpretations. This saves you from manual lookups and provides research-backed context for each variant.
Get Bloodwork to Complete the Picture
Schedule a comprehensive blood panel if you have not had one recently. Key markers to request: vitamin D (25-OH), ferritin, homocysteine, fasting glucose, lipid panel, CRP (inflammation), and thyroid panel (TSH, T3, T4). Use the results alongside your DNA data for the most personalized recommendations.
Make Evidence-Based Adjustments
Based on your combined DNA and bloodwork insights, make targeted changes to your routine: adjust supplement forms and doses, modify your diet based on your genetic metabolism, and choose exercise types that match your genetic profile. Track results with follow-up bloodwork every 3-6 months to confirm your adjustments are working.
Consult Professionals for Significant Findings
If your results include variants associated with serious health conditions, consult a genetic counselor or healthcare professional. Wellness-focused SNPs are for optimization, but clinical-grade results and professional interpretation are essential for medical-grade decisions.
Frequently Asked Questions
Can I interpret my DNA raw data without a genetics degree?
Yes. The basics of reading your raw DNA file are straightforward once you understand the format. Each line contains a marker ID (rsID), the chromosome it sits on, its position, and your genotype (the two letters representing the alleles you inherited). You do not need specialized training to look up individual SNPs and understand what published research says about common variants. However, interpreting complex gene interactions or rare variants should involve a genetic counselor or qualified professional.
Is my 23andMe raw data the same as a clinical genetic test?
No. Consumer DNA tests from 23andMe, AncestryDNA, and TellmeGen use genotyping arrays that check specific known positions in your DNA. Clinical genetic tests often use whole-exome or whole-genome sequencing, which reads every base pair. Consumer tests are excellent for wellness-related SNPs but should not be used to diagnose genetic diseases. If you have concerns about inherited conditions like BRCA mutations or Lynch syndrome, consult a genetic counselor for clinical-grade testing.
Do my DNA results ever change or expire?
Your DNA sequence itself does not change over your lifetime, so your raw data file remains valid indefinitely. However, scientific understanding of what specific SNPs mean is constantly evolving. A variant classified as "uncertain significance" today may be reclassified as research progresses. This is why periodically re-analyzing your same raw data with updated tools can yield new insights even without a new test.
What should I do if my DNA results show a "risk" variant?
First, understand that "risk" in genetics is about probability, not certainty. Having a risk allele for a condition means your statistical likelihood is higher than average, but most common variants only shift risk by small amounts. For wellness-related SNPs like MTHFR or VDR, the "risk" often just means you may benefit from a different form of a supplement or a dietary adjustment. For variants associated with serious conditions (like APOE4 and Alzheimer's risk), consult a healthcare professional or genetic counselor before making decisions.
How do I combine DNA results with my blood test results for better insights?
DNA tells you about genetic predispositions (what your body is built to do), while bloodwork tells you what is actually happening right now. For example, a VDR variant suggests you may need more vitamin D, and a blood test confirms whether your current levels are actually low. The combination creates actionable guidance: if both your genes and your blood tests point to the same issue, the recommendation becomes much stronger. Platforms like HOP automate this by cross-referencing your uploaded DNA data with your lab results to generate personalized wellness routines.
Medical & Genetic Disclaimer
This article is for educational and informational purposes only. It does not constitute medical advice, genetic counseling, diagnosis, or treatment. Consumer DNA test results reflect common genetic variants studied in population research and may not apply to every individual. Genetic predisposition does not guarantee any specific health outcome.
Always consult a qualified healthcare professional or certified genetic counselor before making changes to your diet, supplement regimen, or exercise program based on genetic information. If you discover variants associated with serious inherited conditions, seek clinical-grade confirmatory testing through a healthcare provider.
The FDA classifies consumer DNA wellness tools as general wellness products -- they are not medical devices. Consumer genotyping should not replace clinical genetic testing for diagnostic purposes.
Turn Your Raw DNA Data Into Actionable Health Insights
Stop staring at hundreds of thousands of rows of raw data. HOP automatically extracts your health-relevant SNPs from 23andMe, AncestryDNA, or TellmeGen files and combines them with your bloodwork for truly personalized wellness routines.
Supplements matched to your genetic needs. Meals adapted to your metabolism. Exercises optimized for your muscle fiber type. All updated automatically as you add new lab results.
Get Started with HOPDNA analysis available with Longevity Premium subscription. Upload once, benefit forever.