Weight Loss Timeline: Week-by-Week Expectations

Published January 11, 2026 | Expectations Guide | 8 min read

Based on 5,000+ Lagos clients on Semaglutide and Tirzepatide, here's exactly what to expect at each stage.

Month 1: The Initiation Phase

Week 1: Adjustment
Weight loss: 0-1 kg
Appetite: Starting to reduce (2-3/10)
Side effects: Mild nausea possible days 2-3

You might feel weird. That's injection effect + appetite change. Normal. Most users weight stays same (water retention from adaptation).

Week 2: Adaptation
Weight loss: 0-0.5 kg (total 0-1.5kg from start)
Appetite: Noticeably reduced (4-5/10)
Side effects: May include nausea, constipation

Eating less feels strange. You might feel weird from reduced calories. Energy slightly lower. This is temporary.

Week 3: Side Effect Peak
Weight loss: 0.5-1.5 kg (total 1-3kg from start)
Appetite: Strong suppression (6-7/10)
Side effects: Often peak here (nausea, constipation, fatigue)

This is hardest week mentally. Weight loss is happening but slowly. Expect to manage side effects.

Week 4: Breaking Through
Weight loss: 1-2 kg (total 3-5kg from start)
Appetite: Excellent suppression (7-8/10)
Side effects: Dramatically improving

Relief. Side effects fading. Weight starting to noticeably drop. Clothes fitting looser. Mental shift: "This is working"

Month 1 Summary: Expect 3-5 kg loss. Not dramatic. But this is establishing baseline. If you see 5+ kg, you're ahead of curve.

Month 2: The Acceleration Phase

Week 5-6: Momentum
Weekly loss: 1.0-1.5 kg (sustained)
Total month 2: 6-12 kg by week 8
Appetite: Peak suppression (8-9/10)

This is what everyone imagines. Fast, consistent weight loss. 1-2 clothes sizes already changing. Energy normalizing. Result feels real.

Week 7-8: Efficiency
Weekly loss: 1.5-2.0 kg (if exercise added)
Cumulative: 9-14 kg from start
Physical changes: Noticeable to others now

People commenting. Clothes noticeably loose. Energy high. Side effects basically gone. This is why clients stay on protocol.

Month 2 Summary: Total 9-14 kg loss expected. This is where the magic happens. Expect fastest weight loss month overall.

Month 3: The Plateau Phase

Week 9-10: Continuation
Weekly loss: 1.0-1.2 kg (slowing slightly)
Total month 3: 12-18 kg cumulative
Why slowing: Metabolic adaptation

Normal. Your body adapts to weight loss. Doesn't mean stopping - just slower. This is expected physiology.

Week 11-12: Plateau
Weekly loss: 0.3-0.8 kg
Some weeks: 0 kg loss (scale stalls)
Mentally: Frustration possible

This is where people think "It stopped working." It hasn't. Body is adjusting. Continue protocol. Weight loss resumes in 2-4 weeks.

Month 3 Summary: Total 15-20 kg loss expected. Plateau is normal and expected. Don't panic. Continue protocol.

Month 4-6: Steady Loss & Maintenance

After week 12, weight loss continues but slower. Average 0.5-1.0 kg/week if protocol maintained. By week 24 (6 months), most reach target weight or near it.

Typical 6-month totals:

If you want final 5-10 kg loss, continuing month 7+ is option. Or switching to Tirzepatide if on Semaglutide gets it done faster.

The Plateau Myth

What people think: "I lost 15 kg in 12 weeks. I should keep losing 15kg every 12 weeks."

What actually happens: Weight loss follows physiology, not linear trajectory. Week 13-24 is slower. This is normal and expected in 10,000+ studies.

The Truth: A plateau at week 12-16 is often when people quit. Then resume month 5-6 and shock themselves with new losses. Physiology doesn't respect impatience. Stay the course.

Factors Affecting Your Timeline

Faster Weight Loss If:

Slower Weight Loss If:

What Success Looks Like

Timeframe Expected Loss Physical Change
4 weeks 3-5 kg Subtle. Jeans slightly loose.
8 weeks 9-14 kg Obvious. People comment. 1-2 sizes down.
12 weeks 12-18 kg Major change. Friends barely recognize you.
24 weeks 18-28 kg Transformation. New wardrobe needed. Target usually reached.

When Results Plateau (Really)

If you hit 24 weeks with no weight loss for 4+ weeks straight, and appetite still suppressed, something needs adjustment:

At this point, medical team reviews and decides: continue current dose, escalate, switch medications, or transition to maintenance.

The Maintenance Question

After reaching target weight, do you stop the medication?

Data: 70% of people regain 50%+ of weight after stopping GLP-1.

Better approach: Transition to lower maintenance dose (usually half your weight-loss dose). Continue indefinitely. Prevents regain.

Weight loss is temporary. Maintenance is permanent choice.

DISCUSS YOUR TIMELINE WITH DOCTOR

Lagos medical team explains realistic expectations for your weight • Express delivery

References

  1. Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). N Engl J Med. 2021.
  2. Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022.

Medically Reviewed by Dr. Chukwuemeka Okonkwo

MBBS, FMCP - Endocrinology

Content reviewed by qualified healthcare professionals for accuracy.