Caffeine and nicotine can actually halt breast enhancement altogether.  Removing or limiting soda, tea, and coffee in your diet can increase your body's response to all of the herbal pills mentioned above. Try to limit or stop smoking while you take herbal pills.

Other factors that can affect your results will be:
Too much stress, not enough sleep, and an unhealthy diet. 

You wouldn't expect to be able to run a marathon after eating nothing but fast food for weeks. Your body wouldn't be in any shape to compete. Your body also performs better on seven-eight hours of sleep and stress levels that are at a minimum.     

Obviously there are factors while taking Breast Enlargement pills that no one can prepare for or keep under control, but eliminating highly stressful situations and eating a balanced diet can help promote a better response to these herbal pills. 

Time will play an important part in results:
Some women may not realize how stressful their life really is, and may expect a Breast Enlargement pill to enlarge their bust within 4 weeks. Studies have shown that most supplements will not do this.  Just like puberty didn't happen over the course of one month, usually a breast pill will not change your cup size in one month. Some women may need to take herbal breast pills up to a full year to see a cup size increase.  Whereas, other women may see larger breasts or results within 2-3 months.  Each individual will respond to the ingredients differently based on body chemistry as well as external factors already mentioned.