Telogen effluvium affects up to 70% of bariatric surgery patients within 3 to 6 months of the procedure, making it one of the most predictable and distressing side effects of weight loss surgery. myhairline.ai lets you document the shedding and recovery phases with density data your bariatric team can use to guide nutritional intervention.
This content is for informational purposes only and does not constitute medical advice.
Why Bariatric Surgery Causes Hair Loss
Bariatric surgery triggers hair loss through two overlapping mechanisms: metabolic shock and nutritional deficiency.
The surgery itself places the body under acute physiological stress. Rapid caloric restriction in the weeks following the procedure forces a large percentage of hair follicles out of the anagen (growth) phase and into the telogen (resting) phase. This synchronized shift is called telogen effluvium, and it produces visible shedding 3 to 4 months later when those resting hairs fall out simultaneously.
The second mechanism is chronic. Malabsorptive procedures like Roux-en-Y gastric bypass and biliopancreatic diversion reduce the intestinal surface area available for nutrient absorption. Even with supplementation, patients frequently develop deficiencies in iron, zinc, protein, biotin, and vitamin D, all of which are critical for hair follicle function.
Shedding Timeline After Bariatric Surgery
| Months Post-Surgery | Phase | What to Expect |
|---|---|---|
| 0 to 3 | Latent | No visible shedding, follicles entering telogen |
| 3 to 4 | Onset | Increased shedding in shower, on pillow, in brush |
| 4 to 6 | Peak | Maximum daily hair loss, diffuse thinning visible |
| 6 to 9 | Stabilization | Shedding rate decreasing, new growth beginning |
| 9 to 12 | Recovery | Density rebuilding, visible regrowth |
| 12 to 18 | Full recovery | Most patients return to pre-surgery density |
Tracking density across these phases creates a timeline that separates expected shedding from abnormal loss that requires intervention.
Step 1: Establish a Pre-Surgery Baseline
The most valuable density reading you will ever take is the one before your surgery. This baseline becomes the reference point for every subsequent scan.
Take your baseline scan with myhairline.ai 1 to 2 weeks before your scheduled procedure. Record your current Norwood stage, overall density score, and zone-by-zone readings. If you have any pre-existing androgenetic alopecia, note this separately, as bariatric shedding will compound existing pattern loss.
Save screenshots of your baseline heatmap. Your surgical team may not be familiar with hair density tracking tools, so having visual references makes the data easier to share during follow-up appointments.
Step 2: Set a Monthly Scanning Schedule
Consistency is critical for meaningful tracking. Set a recurring monthly reminder to scan with myhairline.ai on the same day each month, under similar lighting and hair conditions.
Monthly scans capture the full arc of the shedding curve. If you only scan during peak shedding, your data will look alarming without the context of gradual onset and recovery. A complete timeline from months 1 through 12 tells the whole story.
For the best comparison data, follow the same photo protocol each time: dry hair, no product, consistent overhead lighting, and a front, top, and crown angle.
Step 3: Log Nutritional Data Alongside Density Readings
Hair density alone does not tell your bariatric team why shedding is occurring. Pairing density readings with lab values creates a correlation record that guides treatment decisions.
Key values to log:
- Ferritin (iron storage): Levels below 40 ng/mL are associated with hair shedding. Many bariatric patients drop below this threshold within 6 months of surgery.
- Zinc: Deficiency is common after malabsorptive procedures and directly impairs hair follicle cycling.
- Protein intake: Most bariatric programs recommend 60 to 80 grams of protein daily. Falling below this target accelerates hair loss.
- Vitamin D: Levels below 30 ng/mL are linked to telogen effluvium.
- Biotin: While true biotin deficiency is rare in the general population, it is more common after bariatric surgery due to reduced absorption.
When you share your myhairline.ai timeline with your surgical team, annotate it with the dates of blood draws and any supplement adjustments. This turns your data into a clinical tool rather than just a personal record.
Step 4: Identify Normal vs. Abnormal Shedding Patterns
Not all post-bariatric hair loss follows the expected pattern. Your tracking data helps distinguish between:
Expected telogen effluvium: Diffuse thinning across the entire scalp, beginning 3 to 4 months post-surgery, peaking at 4 to 6 months, and resolving by 12 months. Density drops evenly across all zones.
Nutritional deficiency shedding: May begin later (6+ months), often more severe, and may not resolve until deficiencies are corrected. Your density timeline will show a plateau or continued decline past the 6-month mark instead of the expected recovery curve.
Androgenetic alopecia progression: Pattern-specific loss concentrated at the temples and vertex. If your tracking shows that frontal recession or vertex thinning is accelerating beyond what the rest of your scalp is doing, this may indicate underlying male pattern hair loss that was previously masked by fuller overall density.
If your density readings show no recovery by month 9, or if shedding accelerates after month 6, share your timeline with your surgical team immediately. This is a signal that nutritional intervention needs adjustment.
Step 5: Share Your Timeline with Your Bariatric Team
Most bariatric surgeons and dietitians expect some degree of hair loss in their patients, but few have access to objective density data. When you bring your myhairline.ai timeline to a follow-up appointment, you provide:
- A visual record of density change over time
- Correlation points between lab values and hair response
- Evidence of whether the shedding follows the expected 3 to 12 month arc
- Data to support requests for additional bloodwork or supplement adjustments
This is especially useful when tracking hair loss after weight loss over extended periods, as some patients experience secondary shedding episodes if they undergo additional procedures or hit new weight loss milestones.
What Recovery Looks Like in Tracking Data
Recovery from post-bariatric telogen effluvium typically follows a predictable density curve. After the peak shedding phase, you will see:
- Month 6 to 8: Shedding rate drops. New short hairs become visible at the hairline and part.
- Month 8 to 10: Density readings begin trending upward. The heatmap shows green zones expanding.
- Month 10 to 14: Most zones return to within 10% to 15% of the pre-surgery baseline.
For patients on concurrent hair loss treatments like finasteride (which halts further loss in 80% to 90% of users) or minoxidil (40% to 60% regrowth rate), tracking separates the effects of bariatric recovery from treatment response. Understanding your telogen effluvium recovery timeline helps set realistic expectations for both you and your medical team.
Patients who track consistently report lower anxiety about their shedding because they can see the recovery trend forming in their data, even before it is visible in the mirror.
Get your free pre-surgery baseline scan at myhairline.ai/analyze