Brief Answer:
Explained

Detailed Answer:
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I appreciate your concern

Vyvanse is lisdexamphetamine (L- lysine-D-amphetamine )its prodrug the active metabolite is dextroamphetamine which is central nervous system stimulant used for treatment for attention defecit hyperactivity disorder also used for moderat to severe binge eating disorders
Vyvance only contains the one enantiomer which is more active .
Its drug of abuse and may be habit forming
Procentra is dextoamphetamine which is too a central nervous system stimulant its also used to treat ADHD and nacrolepsy.
The major diffenrence between vyvance and other amphetamines is that vyvance is a prodrug which is an inactive form its is broken down in body to release the active form.
It has an amino acis lysin to it which is degraded by an enzyme in body since it must be cleaved to release active form vyvance lasts longer in system then do straight amphetamines as result single dose taken early in day can stay in body untill evening
Vyance has reduced addiction potential because its slowly enters the system generally faster the drug enters blood more it has addiction potential
Vynace solubility is not affected by digestive ph thay much as compare to other drugs
Its said that its cleared from body without system build-up
If you feel that its not helping any more you can talk to your doctor about that as to increase the dose or to change the medication as its not necessary that a drug will have same effect in everybody overtime

please consult your doctor before taking any further course of action

Wishing you best of health

Hope it helps
Thanks

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