Thanks for your question. When PRP is injected, the follicles are flooded with your own growth factors. If your hair loss is due to inflammation, the PRP will be very effective at stopping shedding and stimulating growth. If your hair loss is purely hormonal, the PRP is probably the wrong treatment. As you are already on propecia, the hormonal treatment is in place... and the PRP is acting on the inflammatory pathways. Studies show that when PRP works, it is maximally effective at stopping shedding 4 months after one treatment, and you should start to see an improvement in hair caliber thickness between 3-6 months. If each hair gets thicker, you should see an improvement in overall volume. If you have no inflammatory component to your hair loss, you may see little or no benefit. Of note, some studies are suggesting 2 if not 3 (or more) treatments of PRP are necessary to reach an effect. That being said, I would wait one or two more months... consider one more treatment... but proceed with caution. Of note, there are 8 systems of PRP... not all of these treatment systems are the same. In fact, they are very different. Make sure you are using a long-acting PRP. Hair grows so slowly, and you need to make sure the PRP is going to last to stimulate the follicles. Lastly, I do not use ACell as it has real risks. I know this is a lot of information... and I hope this helps you.