Break out of a cycle of dependency whereby the addict relies on you and, in turn, your assistance inadvertently helps the person keep up the addiction. This is called negative enabling. Learn to say "no" and commit yourself to it; it is perhaps one of the most important components of bringing about transformation in an addict. It's also important to note that the addict will likely not respond well to your commitment to saying "no" since she may be used to getting what she wants and when. If the person is a family member or friend, you'll need to think about money in particular. Decide if you are willing to lend the person money or not. Many people don't like to lend money knowing that it will be spent on drugs, whilst others see it as stopping the addict from perhaps committing crime and getting into further trouble if she is caught. Make up your mind about this matter and stick to it. If you don't want to lend money, firmly let the person know the reasons you are unwilling and don't waver. If you are willing to lend to the person, have her sign debtor's notes for each loan and let her know that you plan to pursue any unpaid debts. If the person does let you down, stop lending to her. In addition, don't enable the behavior or try to keep up with the person by joining in the drug use. You need to keep yourself safe first and foremost. Avoid covering up or making excuses for the person's behavior or taking over the person's responsibilities (whether they be work, family, or otherwise). Doing so shields the person from the negative consequences of her behavior. She needs to learn that what she is doing has adverse consequences. Very few people addicted to heroin manage to complete a detox and remain clean on their first attempt. If your loved one does relapse, don't lose faith and do something drastic like disown her or kick her out. Remember that most people relapse a few times before they make it. Even when the person is past the withdrawal stage, recovery is not yet a certain thing as it encompasses much more than just getting rid of the person's physical dependency on heroin. Heroin addiction is not all physical. When someone is trying to recover from heroin addiction, they also need to deal with the mental aspects of their addiction and the triggers that led the person to engage in the behavior in the first place. Even though the withdrawal symptoms might have gone, the mental addiction will still be there, urging her to use again. Thus, treatment will have to involve dealing with those underlying issues in order to truly remove the impetus to relapse. If (or when) the person fails, don't take it as a personal insult and instead offer support for the next time she tries. Be supportive and try not to be suspicious of the person all the time; appreciate that it is hard to overcome a heroin addiction and show compassion for this trial. Instead of nagging the person when she slips or falls on the path to recovery or trying to control her every move and behavior, offer understanding and empathy. The very fact that the person wants to try to get better and beat the addiction is encouraging. Remember that recovery is not linear, like going simply from point A to point B. There are lots of ups and downs. Don't keep asking the person if she is still clean or lecturing her about not starting again. If you're constantly nagging the person, she will begin to lose trust and comfortability with you and may even start keeping things from you. Offer provide praise and encouragement when the person does something to further her recovery or as a way to mark a milestone on the path to recovery (such as one-week sober or 30 days sober). This is also called positive enabling, which refers to behaviors that encourage change in a person addicted to drugs. Enable the person to continue her recovery and her path of change by reminding her that you love her and that you too are committed to her betterment. Once the person is receiving treatment, whether that be by entering a rehabilitation center, seeing a therapist, or going to meetings, remain an active part of their recovery process. Getting the person to get help and treatment with only the first stage of recovery. Your loved one will need your support in order to carry on with the treatment and be successful in beating the addiction. Show the person that you are invested in her and her long-term recovery. One way to stay involved is to try to attend therapy sessions or meetings that allow guests of people addicted to drugs. This may also help you build understanding and empathy as you will come to learn about heroin addiction and how it affects people. Inquire about the person's recovery. However, rather than ask the person in a Q-and-A format or other style that resembles an interrogation rather than a conversation (e.g. "Did you go to a meeting today?";"Did you talk in therapy today?", etc.), consider asking open-ended questions that allow the person to shape the narrative they want to tell (e.g., "How have the meetings been going?" and "Have you learned anything new about yourself throughout this process?").

Summary:
Don't enable the behavior. Don't make excuses for the person. Prepare for relapses. Show empathy and patience. Engage in positive reinforcement. Remain present throughout recovery.