this is "nightline." >> tonight, natural viagra? >> oh. >> what if you could fix your sexless relationship with a simple herbal repry. tonight, we're on a quest to hunt down a natural libido lift for men and women. does it work? plus, 90-day fiance. she's from south africa. he's from philly and they have only a few weeks to put a ring on it before the visa runs out. couples in extreme long distance relationships put to the test. and, she's behind smash hits like "book clap" and "fancy." but she's about to be so famous. tonight, why the british import is breaking a rule. and her own way to super stardom. ♪ i want to break the rules >> but first, the "nightline"

five. >> take zzzquil and sleep like a baby. like a bear. how about like your on vacation in this place? sleep like you haven't seen your bed in days. no, in weeks. sleep like the kids went to nan a's house for the whole weekend. sleep like you just took zzzquil. the non-habit forming sleep aid from nyquil. because sleep is a beautiful thing. >> number one in just 60 seconds.

good evening. we start tonight with a very personal question. need a boost in the bedroom? if so, you're not alone. sexual enhancement drugs are multibillion dlarl business in

the u.s. tonight, we're going on an adventure, in dense rain forest where a miracle cure may be hiding. now, u.s. companies want it, badly. they have to find it, first. here's abc's gloria riviera. >> reporter: we are deep in the malaysian rain forest on a quest. to find what may be nature's most potent after deez ya called tongkat ali. officially dubbed nature's vie gag are. our guide, an american who re r refers to himself as the medicine hunter. >> you give people tongkat ali. it's chinese new year's fireworks in their pants. it works. >> reporter: and it could be a game change earl in the u.s. a nation who is obsessed with sexual enhancement and driving a multibillion dollar business. >> that bark's different. that bark's different. >> reporter: that is, if we manage to find it. in dense, impossibly hill little

terrain, crawling with predators. >> one drop of that venom could kill all of us plus all our relatives. i want to know about these. >> reporter: chris is one of the herbal industry's hired guns. >> what do you do with it? he scours the globe investigating natural remedies. racing around like a kid opening presents. that promise to make us younger, stronger and sexier. >> right now it's about $100 billion a year globally. this is a big, big business. >> reporter: and he's staking his reputation on tongkat ali, an herb already successful in malaysia. >> really good medium for congress cat ali. >> reporter: that most americans have never heard of. >> probably the single most highly prized plant medicine in this country. >> reporter: but chris wants to make tongkat ali a household name. and he's convinced naturex, one of the herbal industries biggest

players that they'll make millions if they back his plan. chris needs to find a steady source that can sustain american demand. television star. our secret weapon, a chain smoking local tribesman who knows the turf. what's the plan? just go up and look for it. that's the plan. he's so fast. still hasn't seen any big tongkat ali, but he says he thinks we'll find it. finally, over an hour and a half into our brutal hike, pay dirt. is this it? oh, my god. we found one. >> this one right here. >> reporter: finding it is only half the battle. >> this is going to be so hard to get out. >> reporter: it's the root of the tongkat ali tree, not the bark or the leaves that has medicinal value, that so-called natural vie yag gra component. this has to happen every time?

>> every single time. >> reporter: wild tongkat ali is prized, and believe it or not, nobody's figured out how to farm it, which worries chris, because there may be not enough trees to satisfy a mass market in the u.s. >> are we damaging the wild supply? are we harvesting just enough that it's sustainable? >> reporter: whoa. six grown men trying to get this thing out of here and it's not moving. two hours and a lot of creative ma givering later -- >> yeah. >> reporter: wow. they unearth a monster haul. >> big monster root to pull out of the forest when you're three feet tall. >> reporter: that is insane. this root will net him a grand total of 25 u.s. dollars. he's smiling because he knows this is good stuff. it may seem crazy. all that work for only one root. but chris themes with local partners and enough guides, his

plan to make tongkat ali a block buster herb in the u.s. might actually work. back at the house, we toast our success with a traditional brew that he claims builds endurance for his daily grind. better sex is just a side benefit. a lot of americans may soon be taking tongkat ali for sex. do you think that's crazy? >> it tastes okay, but you have to drink it very often. >> reporter: you have to drink a lot. oh, and by the way, he's 40 years old and he's the father of nine children ch. >> that's perfect. >> reporter: ah. it's bitter. oh. ok, so, now i know it tastes gross, but how does it work? >> improves muscle strength and endurance. how many kilos do you get in terms of the root from these? >> reporter: this scientist working for m.i.t. and the

malaysian government has stud dimmed the effects. >> it increases the male hormone level. >> reporter: and says taking tongkat ali can boost low testosterone and sperm count. >> there are lots of different ways to get a sexual function, but certainly, boosting testosterone is one of them. >> reporter: and chris says, unlike most sexual enhancers, this one helps women, too. up to 1 in 3 american women suffer with low sexual desire. >> after having my first child, i didn't want to have sex. >> reporter: but 34-year-old alyssa roberts is one of the few that actually managed to get her hands on tongkat ali. >> within five days, my husband noticed something was different. i had more desire for him. >> reporter: the science is shaky, but we did find several studies, some of them industry-sponsored, that support the claim. is it really an alternative to vie yag gra? >> will it work as quickly? no.

but it won't cause potentially heart attack, stroke, deafness or blindness. >> reporterpg(alet's be clear. tongkat ali does not treat e reck tile dysfunction, so, it's not a replacement. but herbs have their own set of risks. critics complain that fda oversightle of the entire industry is far too lenient. should herbal supplements be regulated the same way drugs are? >> herbal supplements are not drugs. here, you have ginger, you know, from india. we have green coffee from africa. >> reporter: chris's boss is sales director for naturex. selling processed herbs to most major brands. he sails more robust regulation would drive costs too high. so, this is how it comes in, absolutely raw. >> yes. >> reporter: and know they have trusted quality control standards. herbal manufacturers are know or the youls for cutting corners.

>> there's some bad apples. >> the real question is, you know, who are the xeechls who are making good products. who are the ones doing it right? twho are the ones that are just making a fast buck and putting out garbage? >> very high quality. >> reporter: after chris's expetition, naturex finally decided to roll the dice on tongkat ali. >> it's a natural, easy and affordable way to regain your manhood, in a way. >> reporter: regain your manhood. >> right. >> reporter: or womanhood, because even an herbal e van jell list like alyssa won't have the to search ver far to reclaim her mojo, in the bead room and beyond. >> our sex life is great now. for every ailment, there is an herb. and people are starting to pay attention. >> reporter: this is where the medicine hunter earns his credit. for "nightline," gloria riviera, malaysia. next, couples facing a split do to immigration laws find a fix. but is it real? and you'll never guess how pop

star charley xcx actually comes up with her smash hits, like "boom clap." ♪ come on to me ♪ come on to me now ♪ boom clap a mess? i don't think -- what's that? snapshot from progressive. plug it in, and you can save on car insurance based on your good driving. you sell to me? no, it's free. you want to try? i try this if you try... not this. okay. da! sweered lobster'sory! endless shrimp ends soon! the year's largest variety. like new spicy siriacha shrimp, or parmesan shrimp scampi. as much as you like, any way you like. but it won't last long, so hurry in today. and sea food differently. when folks think about wthey think salmon and energy. but the energy bp produces up here

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we're about to go on an unusual journey with couples from different parts of the world, facing being split up by immigration law. they have to get married fast, or go their separate ways, in separate countries. is it really true love or purely a business transaction? here's abc's reena ninan. >> what is your biggest fear, coming?

>> i would say meeting your family. >> what? >> reporter: it's the fear that most couples face, but this relationship is unusual. >> i definitely never saw myself with an american guy. >> reporter: 21-year-old amy left her south african city of capetown where she enjoyed her single life for her boyfriend, danny, who lives halfway around the world, in a small suburb near philadelphia. >> so much pressure. pressure of me trying to fit into this mold of his life. me trying to fit into a new family. >> reporter: but they have an unexpected pressure. they have 90 days to get married, or else, amy has to leave. >> the next 90 days are going to be like a roller coaster. >> reporter: they are just one of six couples featured in tl c's "90 day fiance." >> america, i'm home! >> reporter: this reality dating show on steroids has a unique

premise. an american brings their foreign-born girlfriend or boyfriend to the united states on a k-1 visa, which allows them to be in this country, legally, for 90 days. >> this is the first time i've ever experienced this deep of a love with a woman. >> reporter: getting approved for the visa isn't easy. couples who barely know each other have to submit stacks of paperwork, endure rigorous interviews and pay thousands of dollars of their own money just to get their fiance into the country. the tlc show pays the american. >> what if i don't like america? >> reporter: that's when the fun begins. if they don't get married, the foreign-born fiance risks being sent back home. >> she's using him for her green card. >> reporter: danny admits that getting his dad's approval isn't going to be easy for amy. when he talks to you, what has he said his reasons for you not getting married? >> he basically poses questions like, are you ready to live in a

world where a lot of people still don't agree with interracial couples? he brought up your kids, like, are you ready to have interracial kids? >> reporter: is it hard -- your potential future father-in-law hat doubts? >> it is hard. because i would want to be accepted by him. >> reporter: but amy and danny are optimistic about their future. so, if you hate to rate your odds, what would you say about getting married? >> 96%. >> reporter: that's pretty good. what would you say? >> i was going to say 100%. >> reporter: wow. he's 4% more positive than you. >> he always is with everything. >> reporter: but not every couple has as rosy a forecast. take cassia and jason. they met on facebook while she was dating jason's friend. >> we did a lot of texting. we did some skype. >> reporter: cassia, 15 years younger than jason, lives with

him, her 38-year-old fiance, in spring hill, florida. the two have an online business selling se ing second-hand good. they relied on social media during the beginning of their relationship. never meeting in person. hello. >> finally. >> are you still mad at me? >> yes. >> reporter: it took six months to win jason over. she convinced him to apply for the via. >> she said, you want to be my boyfriend? five, six months later, i went down to brazil in july of 2013. >> reporter: cassia says she gets bored living in a small town, but she's won the heart of her father-in-law who lives in the home with the couple. >> you got that on the half price rack? >> reporter: as for jason's friend? >> they always say to him, oh, my god, i'm dating with her and i said, what the [ bleep ], it has nothing to do with that. >> reporter: and another problem she has?

american bathing suits. >> american bikini, look at this. i cannot wear this on the beach. >> reporter: despite the challenges, they say their love is real. but jason did have his doubts at first. >> it did cross my mind that she may havelterior motives. >> reporter: so did his family. jason's brother shared his thoughts about cassia through a gift. >> at the time, he joked around, calling her green card. he actually gave me the movie "green card" for christmas. >> reporte >> your marriage, of course, gives you automatic residency status. >> reporter: but jason says this is not about getting cassia a green card. and they have all their documents to prove it. for danny and amy, their relationship may be easier to prove, but it's still not easy. and how to you prove that this is a genuine relationship and not for show?

>> we did the show through facebook messages. we had to show pictures, just, it all. >> reporter: so, day 89, if you both of you realize, this is not meant for us, we're not meant to get married, would you still help her get a green card? >> that's weird. i didn't think of that. i have no idea. >> whoa. um -- no, i would want to go back home. >> reporter: will they stay together? the couples are in the midst of figuring it all out. >> we worked hard and having this relationship, we've worked hard at keeping everything in line and this is real. >> reporter: for "nightline," i'm reena ninan in philadelphia. next, boom, clap. singer charli xcx reveals the secrets behind her chart-topping hits. ♪

♪ come on, try a little ♪ nothing is forever ♪ there's got to be something better than in the middle ♪ ♪ me and cinderella ♪ we put it all together ♪ we can drive it home ♪ ♪ with one headlight [ male announcer ] great rates for great rides. geico motorcycle. see how much you could save. the setting is perfect. but then erectile dysfunction happens again. you know what? plenty of guys have this issue, not just getting an erection, but keeping it. well, viagra helps guys with ed get and keep an erection. and you only take it when you need it. good to know, right? if ed is stopping what you started... ask you doctor about viagra.

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charli xcx is behind some of billboard's hottest hits. so, why does she still consider herself the anti-pop star? "nightline" co-anchor dan harris went out on the town with the singing sensation to find out. >> reporter: what do three of the most insanely catchy songs in recent memory have in common? ♪ i don't care ♪ i love it >> reporter: "i love it" by icona pop. "boom clap" from the movie "the fault in our stars." ♪ i'm so fancy

>> reporter: and "fancy" by iggy azalea. ♪ from l.a. to tokyo >> reporter: here's the answer. they were all written or co-written by a 22-year-old english woman you may have never heard of. her stage name, charli xcx. and this, radies and gentlemen, is the secret to how she works. >> really just random and a lot of, like, yelling and something kind of comes out. >> reporter: correct. that is how she comes up with her unshakable ear worms. listen to how the process worked when she came up with the hook for "fancy." >> i want to record my initial reaction, my first reaction to the song. and that will generally be me going -- just, like, completely, like, gibberish and then i'll kind of do that a couple of times until i'm happy with the melody, cut it up. and then lyric it and then it's done. >> reporter: so, your nonsystem definitely works. >> it works, but you haven't

heard all of the songs that didn't work. >> rorter: charlotte grew up outside of london and got into music at the age of 14. on this night, she is performing at new york city's historic webster hall. your lyrics, they have a lot of attitude. at times can be brash and bratty. you don't seem that way. >> well, you haven't seen me on stage yet. ♪ i don't want to go to school ♪ i want to break the rules >> reporter: her new song, "break the rules," has become an anthem for young rebellious souls. >> it's very tongue in cheek. it's one of those songs that i think kind of belongs in the '90s in, like, a shampoo spice girls kind of realm, like, it's a song that's like so bad it's good. ♪ i want to break the rules >> reporter: with her secondal

billi but coming out and a tour with katy perry, charli xcx is poised to explode. >> peace out, good night. i'm charli xcx. >> reporter: for "nightline," this is dan harris in new york. >> talented and charming. not a bad combination. thank you for watching abc news. tune in to "good morning america" tomorrow and, as al always, we're online at abcnews.com. good night, america. you got any grout? i need grout. don't give it to him. he wants to destroy robbie's room, why? i'm building myself a lounge. big lounge. i'm going to call it frank's lounge. lounge. he wants to make a giant bathroom for himself. we're leaving robbie's room just the way it is for when he comes back.

he's not coming back. he's happy where he is. bite your tongue. with any luck, right now he's miserable. then i'll turn ray's room into the lounge. he's not coming back. you never know. just say the word, marie. ymond, have you called robbie? just say thetalk to her.. she's the wife. she's the one who's supposed to call people. come on. you're his brotother. you've never even seen his place, and he and amy broke up. you know, you should over there. yeah, well, i've been busy with-- with ally's shoes and golf balls in the toilet. you have to go over and see his new place, raymond, and report back. what, do you want me to wear a wire? that's up to you. ma, look, why don't you just go there? we're waiting for an invitation. it would be rude for us to just barge in. we're waiting for an invitation.