The keto diet can trigger temporary hair loss for some people, usually a few months after starting, largely because of rapid changes in calorie intake, nutrient availability, and the physical stress of a major dietary shift. This isn't unique to keto specifically. Any significant, sudden diet change can produce a similar effect. I see this fairly often with patients who've recently started a strict low-carb approach.
Key Takeaways
- Keto-related hair loss is usually telogen effluvium, a temporary shedding triggered by the stress of a major dietary change.
- Rapid weight loss and reduced calorie intake, both common when starting keto, are well-established triggers for this type of shedding.
- Nutrient gaps, particularly in protein, iron, zinc, and biotin, can develop on a poorly planned keto diet and contribute to hair thinning.
- This type of hair loss typically appears two to three months after starting the diet and improves once the body adjusts or the diet is modified.
- A well-planned keto diet that includes adequate protein and micronutrients is less likely to cause noticeable hair changes.
Why Diet Changes Can Trigger Shedding
Any sudden, significant change in eating patterns, whether it's keto, another restrictive diet, or a period of very low-calorie intake, can push the body into a mild stress response. Hair follicles are sensitive to this kind of physiological stress, and a common result is more hairs than usual shifting into their resting phase at once, followed by shedding two to three months later.
This same underlying mechanism drives hair loss after childbirth, major surgery, or significant illness. The trigger is different, but the pattern of delayed, temporary shedding is similar.
Nutrient Gaps on Keto
The ketogenic diet's strict carbohydrate restriction can make it harder to get certain nutrients if the diet isn't carefully planned. Biotin, zinc, iron, and adequate protein are all important for healthy hair growth, and any shortfall can contribute to thinning on top of stress-related shedding from the diet change itself.
This is more of a planning issue than an inherent flaw in the diet. People who work with a nutritionist or pay close attention to getting a wide variety of keto-friendly, nutrient-dense foods tend to have fewer issues than those following a more restrictive or poorly balanced version of the diet.
Rapid Weight Loss as a Contributing Factor
Keto often leads to fairly rapid weight loss, especially in the first few weeks, and rapid weight loss itself is a recognized trigger for telogen effluvium, separate from any nutrient deficiency. This is true of rapid weight loss from any method, not just keto specifically, which is part of why crash diets in general are associated with temporary shedding.
Slower, more gradual weight loss tends to be gentler on hair, which is one more reason a measured approach to keto, rather than an extremely aggressive calorie deficit, is generally easier on the body overall.
What You Can Do If You're Experiencing This
If you've started keto and are noticing increased shedding, a few adjustments can help. Making sure you're eating enough protein and a wide variety of keto-appropriate vegetables helps close potential nutrient gaps. Avoiding an overly aggressive calorie deficit, rather than combining keto with severe restriction, reduces the physical stress on your body.
Giving your body time to adjust, usually a few months, before making major additional changes also helps you tell the difference between temporary adjustment shedding and something that needs more attention.
Supporting Hair Through a Diet Transition
Since nutrient support plays a real role here, keeping the scalp environment healthy alongside dietary changes can help. Our RootMD Hair Growth Oil is formulated with saw palmetto, pumpkin seed oil, and rosemary oil to support a healthy scalp environment while your body adjusts to a new way of eating.
If shedding continues well beyond a few months or doesn't seem to be improving, my article on hair thinning versus balding can help you figure out whether something beyond diet is contributing.
