In order to get fuller lips naturally, you need to work with the four parts that your lips are made out of. This includes fat, muscle, blood and water.
To increase fat growth in the lips, apply emu or fish oil mixed with castor oil nightly. This is effective because emu oil and fish oil contain high amounts of Omega-3's which are proven to stimulate fat growth in certain area's when applied. Castor oil is an oil which penetrates each layer of skin much more effectively than many other oils. This helps bring the Omega 3's where you want them.
Also, as oestrogen is the hormone which is responsible for giving women full lips, small noses, big eyes, large breasts and basically anything feminine- having your hormones tested to see if they are in balance is a good idea. Or, as long as you don't suffer from any estrogen dominance symptoms, you may start taking all-natural estrogen enhancing herbal supplements. These are mostly sold under names referring to breast growth, but they are effective in many other ways. Look for pills or tea's containing the following herbs:
Wild Yam Root, Saw Palmetto, Fenugreek, Dong Quai Root, Fennel Seed
Visit this site for symptoms of estrogen dominance before taking.
Facial exercises. Use these to build the muscle around your mouth and fill in your lips. You can watch the video below for some mouth exercises. You might laugh the whole time like I did, but they really are effective.
Increasing blood flow to the lips is the method used in most lip-plumping products, which contain ingredients which irritate the lips so that a small allergic reaction occurs and blood is rushed to the mouth. This is a very temporary reaction, but if done daily (or twice daily) the mouth gets used to this effect and holds more blood in the lips naturally. The way I like to do this, however, does not involve an allergic reaction. I find that using lip-plumpers did not have nearly as much of an effect long-term as using a lip pumper. You may have seen them before- these strange devices you can buy online for literally pumping you lips to draw blood into them. However, I just use a baby bottle or washed deodorant cap (as they are mouth-shaped) and simply suction my lips for a few minutes in the shower in the morning and night, as the warm water helps with the blood flow. I find the dramatic effect (the totally bee-stung look) from this lasts for a few hours, and a slightly plumper look is permanent after a few weeks of doing so.
However, be careful to be gentle with your lips to avoid bruising, and if you are getting lines around your mouth from whatever you are using to suction, find something more comfortable to use.
Another method to increase blood flow is massage. Massage thickens the skin wherever it is done, and increases circulation. Massage your lips in the morning and night by applying some oil to the fingertips and gently pulling them outward, then making a "kiss face" and pushing against your hand. Also, use a soft toothbrush to exfoliate the lips and help circulation.
Using these three methods for the past two months, I see a dramatic difference in my lips and am asked about them all the time by close friends and relatives.
Drink lots of water to keep your lips hydrated.